IPv6 Segment Routing Traffic Engineering (SRv6 TE) policies apply to scenarios where multiple paths exist between a source node and a destination node on an SRv6 network. The device can use an SRv6 TE policy to flexibly steer traffic to a proper forwarding path.

SRv6 TE policy identification

An SRv6 TE policy is identified by the following items:

· BSID—SID of the ingress node (source node).

· Color—Color attribute for the forwarding path. You can use the color attribute to distinguish an SRv6 TE policy from other SRv6 TE policies that are configured for the same source and destination nodes.

· Endpoint—IPv6 address of the egress node (destination node).

SRv6 TE policy contents

As show in Figure 1, an SRv6 TE policy consists of candidate paths with different preferences. Each candidate path can have one or multiple subpaths identified by segment lists (also called SID lists).

· Candidate path

An SRv6 TE policy can have multiple candidate paths. Candidate paths are uniquely identified by their preference values. An SRv6 TE policy chooses a candidate path from all its candidate paths based on the preference values to forward traffic.

Two SRv6 TE policies cannot share the same candidate path.

· SID list

A SID list is a list of SIDs that indicates a packet forwarding path. Each SID is the IPv6 address of a node on the forwarding path.

A candidate path can have a single SID list or multiple SID lists that use different weight values. After an SRv6 TE policy chooses a candidate path with multiple SID lists, the traffic will be load shared among the SID lists based on weight values.

Figure 1 SRv6 TE policy contents

SRv6 TE policy creation

An SRv6 TE policy can be created in the following modes:

· Manual configuration from CLI

In this method, you need to manually configure the candidate settings for the SRv6 TE policy, such as candidate path preferences, SID lists and weights.

· Learning from a BGP IPv6 SR policy route

To support SRv6 TE policy, MP-BGP defines the BGP IPv6 SR policy address family and the SRv6 TE policy Network Layer Reachability Information (NLRI). The SRv6 TE policy NLRI is called the BGP IPv6 SR policy route. A BGP IPv6 SR policy route contains SRv6 TE policy settings, including the BSID, color, endpoint, candidate preferences, SID lists, and SID list weights.

The device can advertise its local SRv6 TE policy settings to its BGP IPv6 SR policy peer through a BGP IPv6 SR policy route. The peer device can create an SRv6 TE policy according to the received SRv6 TE policy settings.

· Automatic creation by ODN

When the device receives a BGP route, it compares the color extended attribute value of the BGP route with the color value of the ODN template. If the color values match, the device automatically generates an SRv6 TE policy and two candidate paths for the policy.

¡ The policy uses the BGP route's next hop address as the end-point address and the ODN template's color value as the color attribute value of the policy.

¡ The candidate paths use preferences 100 and 200. You need to configure the SID lists for the candidate path with preference 200 through dynamic calculation based on affinity attribute or Flex-Algo, and use PCE to compute the SID lists for the candidate path with preference 100. For more information about SID list computation using PCE, see "SID list computation using PCE."

You can also manually create candidate paths for an ODN-created SRv6 TE policy.

SID list creation through dynamic path calculation

SID list creation through dynamic path calculation is supported on the source node of manually created SRv6 TE policies and automatically generated SRv6 TE policies through ODN.

The dynamic path calculation is performed based on affinity attribute or Flex-Algo.

Dynamic path calculation based on affinity attribute

An SRv6 TE policy performs dynamic path calculation based on affinity attribute as follows:

1. Select the links based on the affinity attribute rule.

The SRv6 TE policy selects links containing the bit values associated with the specified affinity attribute as required by the affinity attribute rule.

¡ Link attribute—A 32-bit binary number. Each bit represents an attribute with a value of 0 or 1.

¡ Affinity attribute bit position—The value range is 0 to 32. When the affinity attribute value is N, it is compared with the N+1 bit of the link attribute (from right to left). The affinity attribute applies to the link only if the N+1 bit value of the link attribute is 1.

For example, for affinity attribute name blue associated with bit 1 and affinity attribute name red associated with bit 5, the link selection varies by affinity attribute rule type:

¡ For the include-any affinity attribute rule, a link is available for use if the link attribute has the second bit (associated with affinity attribute blue) or sixth bit (associated with affinity attribute red) set to 1.

¡ For the include-all affinity attribute rule, a link is available for use if the link attribute has both the second bit (associated with affinity attribute blue) and sixth bit (associated with affinity attribute red) set to 1.

¡ For the exclude-any affinity attribute rule, a link is not available for use if the link attribute has the second bit (associated with affinity attribute blue) or sixth bit (associated with affinity attribute red) set to 1.

2. Select the links based on the specified metric.

The SRv6 TE policy supports the following metrics:

¡ Hop count—Selects the link with minimum hops.

¡ IGP link cost—Selects the link with minimum IGP link cost.

¡ Interface latency—Selects the link with the minimum interface latency.

¡ TE cost—Selects the link with minimum TE cost.

After path calculation, the device sorts all link- or node-associated SIDs on the path in an ascending order of distance, and creates an SID list for the SRv6 TE policy. During SID selection, End SIDs take precedence over End.X SIDs.

Dynamic path calculation based on Flex-Algo

The SRv6 TE policy uses the specified Flex-Algo to perform dynamic path calculation. After path calculation, the device sorts all link- or node-associated SIDs on the path in an ascending order of distance, and creates an SID list for the SRv6 TE policy. During SID selection, End SIDs take precedence over End.X SIDs.

For more information about path calculation based on Flex-Algo, see IS-IS configuration in Layer 3—IP Routing Configuration Guide.

SID list computation using PCE

On an SRv6 TE policy network, an SRv6 node can act as a Path Computation Client (PCC) to use the paths computed by the Path Computation Element (PCE) to create SID lists for a candidate path.

Basic concepts

· PCE—An entity that provides path computation for network devices. It can provide intra-area path computation as well as complete SID list computation on a complicated network. A PCE can be stateless or stateful.

¡ Stateless PCE—Provides only path computation.

¡ Stateful PCE—Knows all path information maintained by a PCC, and performs intra-area path recomputation and optimization. A stateful PCE can be active or passive.

- Active stateful PCE—Accepts path delegation requests sent by a PCC and optimizes the paths.

- Passive stateful PCE—Only maintains path information for SID lists of a PCC. A passive stateful PCE does not accept path delegation requests sent by a PCC or optimize the paths.

· PCC—A PCC sends a request to a PCE for path computation and uses the path information returned by the PCE to establish forwarding paths. For a PCC to establish a PCEP session with a PCE, the PCC and PCE must be of the same type.

¡ Stateless PCC—Sends path computation requests to a PCE.

¡ Stateful PCC—Delegates SID list information to a stateful PCE. A stateful PCE can be active or passive.

- Active stateful PCC—Reports its SID list information to a PCE, and uses the paths computed by the PCE to create and update the SID lists.

- Passive stateful PCC—Only reports its SID list information to a PCE but does not use the PCE to compute or update path information for the SID lists.

· PCEP—Path Computation Element Protocol. PCEP runs between a PCC and a PCE, or between PCEs. It is used to establish PCEP sessions to exchange PCEP messages over TCP connections.

PCE path computation

As shown in , the PCE path computation procedure is as follows:

1. The PCC sends a path computation request to the PCE.

2. The PCE computes paths after it receives the request.

3. The PCE replies the PCC with the computed path information.

4. The PCC creates SID lists for the SRv6 TE policy candidate path according to the path information computed by the PCE.

Figure 2 Path computation using PCE

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SRv6 TE policy validity

An SRv6 TE policy must be valid in order to ensure successful traffic forwarding.

The following describes the rules for identifying the validity of an SRv6 TE policy:

1. An SRv6 TE policy is valid only if it has valid candidate paths.

2. A candidate path is valid only if it has a valid SID list.

3. A SID list is valid if none of the following situations exists:

¡ The SID list is empty.

¡ The weight of the SID list is 0.

¡ An SR node and the first IPv6 address in the SID list cannot reach each other.

Figure 3 SRv6 TE policy validity determination

Traffic steering to an SRv6 TE policy

The following modes are available to steer traffic to an SRv6 TE policy:

· BSID—If the destination IPv6 address of a received packet is the BSID of an SRv6 TE policy, the device uses the SRv6 TE policy to forward the packet.

· Color—The device searches for an SRv6 TE policy that has the same color and end-point address that match the color and nexthop address of a BGP route. If a matching SRv6 TE policy exists, the device recurses the BGP route to that SRv6 TE policy. Then, when the device receives packets that match the BGP route, it forwards the packets through the SRv6 TE policy.

· Tunnel policy—In an MPLS L3VPN, EVPN L3VPN, EVPN VPLS, or EVPN VPWS network, use an SRv6 TE policy as the public tunnel to carry the packets of a VPN instance. For more information about the tunnel policy configuration, see MPLS Configuration Guide.

· DSCP—Create color-to-DSCP mappings for an SRv6 TE policy group, and create a tunnel policy that binds a destination IP address to the SRv6 TE policy group. Upon receiving a packet with the specified destination address, the device searches for the SRv6 TE policy containing the color value mapped to the DSCP value of the packet. The device will use the SRv6 TE policy to forward the packet.

The device obtains an SRv6 TE policy group for traffic steering as follows:

¡ Matches the destination IP address in a packet with a tunnel policy associated with an SRv6 TE policy group.

¡ Searches for an SRv6 TE policy group with color and endpoint address matching the color extended community attribute and next hop in a BGP route, and recurses the BGP route to the SRv6 TE policy group.

· 802.1p (or Dot1p)—Create color-to-802.1p mappings for an SRv6 TE policy group, and create a tunnel policy that binds a destination IP address to the SRv6 TE policy group. Upon receiving a packet with the specified destination address, the device searches for the SRv6 TE policy containing the color value mapped to the 802.1p value of the packet. The device will use the SRv6 TE policy to forward the packet.

The device obtains an SRv6 TE policy group for traffic steering as follows:

¡ Matches the destination IP address in a packet with a tunnel policy associated with an SRv6 TE policy group.

· Static route—Configures a static route that recurses to an SRv6 TE policy. The device uses the SRv6 TE policy to forward the packets that match the static route.

· PBR—Directs traffic to an SRv6 TE policy through PBR. The device uses the SRv6 TE policy to forward the packets that match the PBR policy. For more information about PBR, see Layer 3—IP Routing Configuration Guide.

· QoS policy—Redirects traffic to an SRv6 TE policy through a QoS policy. The device uses the SRv6 TE policy to forward the packets that match the traffic classes of the QoS policy. For more information about QoS policies, see the QoS configuration in ACL and QoS Configuration Guide.

· Flowspec—Redirects traffic to an SRv6 TE policy through a Flowspec rule. The device uses the SRv6 TE policy to forward the packets that match the Flowspec rule. For more information about Flowspec, see ACL and QoS Configuration Guide.

· Automatic route advertisement—Advertises an SRv6 TE policy to IGP (IPv6 IS-IS or OSPFv3) for route computation, so as to forward the matching traffic through the SRv6 TE policy.

An SRv6 TE policy supports only automatic route advertisement in IGP shortcut mode, which is also called autoroute announce. Autoroute announce regards the SRv6 TE policy tunnel as a link that connects the tunnel ingress and egress. The tunnel ingress includes the SRv6 TE policy tunnel in IGP route computation.

SRv6 TE policy path selection

After traffic is steered in to an SRv6 TE policy, the SRv6 TE policy selects a forwarding path for the traffic as follows:

1. Selects the valid candidate path that has the highest preference.

2. Performs Weighted ECMP (WECMP) load sharing among the SID lists of the selected candidate path. The load of SID list x is equal to Weight x/(Weight 1 + Weight 2 + … + Weight n).

For example, as shown in Figure 4, Device A first selects a valid SRv6 TE policy by BSID. Then, the device selects a candidate path by preference. The candidate path has two valid SID lists: SID list 1 and SID list 2. The weight value of SID list 1 is 20 and the weight value of SID list 2 is 80. One fifth of the traffic will be forwarded through the subpath identified by SID list 1. Four fifth of the traffic will be forwarded through the subpath identified by SID list 2.

Figure 4 SRv6 TE policy path selection

SRv6 TE policy forwarding procedure

As shown in Figure 5, the SRv6 TE policy forwarding procedure is as follows (BSID-based traffic steering as an example):

1. After Device A receives a packet with destination address 100::1, it searches its IPv6 routing table and determines that the address is a BSID. Then, Device A encapsulates the packet with an SRH header according to the SRv6 TE policy of the BSID. The SRH header contains SID list {10::2, 20::2, 30::2}, where 10::2 is the SID for Device B, 20::2 is the SID for Device C, and 30::2 is the SID for Device D.

2. Device A forward the packet to the next hop Device B.

3. After Device B receives the packet, it obtains the next hop Device C from the SRH, and then forwards the packet to Device C.

4. After Device C receives the packet, it obtains the next hop Device D from the SRH, and then forwards the packet to Device D.

5. After Device D receives the packet, it identifies that the SL value is 0 in the SRH. So Device D decapsulates the packet. Device D deletes the SRH header and forwards the packet according to the destination address of the packet.

Figure 5 SRv6 TE policy forwarding diagram

SRv6 TE policy CBTS

About SRv6 TE policy CBTS

SRv6 TE policy Class Based Tunnel Selection (CBTS) enables dynamic routing and forwarding of traffic with service class values over different SRv6 TE policy tunnels between the same tunnel headend and tailend. CBTS uses a dedicated tunnel for a certain class of service to implement differentiated forwarding for services.

How SRv6 TE policy CBTS works

SRv6 TE policy CBTS processes traffic mapped to a priority as follows:

1. Uses a traffic behavior to set a service class value for the traffic. For more information about setting a service class value in traffic behavior view, see the remark service-class command in ACL and QoS Command Reference.

2. Compares the service class value of the traffic with the service class values of the SRv6 TE policy tunnels and forwards the traffic to a matching tunnel.

SRv6 TE policy selection rules

SRv6 TE policy CBTS uses the following rules to select an SRv6 TE policy for the traffic to be forwarded:

· If an SRv6 TE policy has the same service class value as the traffic, CBTS uses this SRv6 TE policy.

· If multiple SRv6 TE policies have the same service class value as the traffic, CBTS selects an SRv6 TE policy based on the flow identification and load sharing mode:

¡ If only one flow exists and flow-based load sharing is used, CBTS randomly selects a matching SRv6 TE policy for packets of the same flow.

¡ If multiple flows exist or if only one flow exists but packet-based load sharing is used, CBTS uses all matching SRv6 TE policies to load share the packets.

For more information about the flow identification and load sharing mode, see the ip load-sharing mode command in Layer 3—IP Services Command Reference.

· If the traffic does not match any SRv6 TE policy by service class value, CBTS randomly selects an SRv6 TE policy from all SRv6 TE policies with the lowest forwarding priority. An SRv6 TE policy that has a smaller service class value has a lower forwarding priority. An SRv6 TE policy that is not configured with a service class value has the lowest priority.

SRv6 TE policy CBTS application scenario

As shown in Figure 6, CBTS selects SRv6 TE policies for traffic from Device A to Device B as follows:

· Uses SRv6 TE policy B to forward traffic with service class value 3.

· Uses SRv6 TE policy C to forward traffic with service class value 6.

· Uses SRv6 TE policy A to forward traffic with service class value 4.

· Uses SRv6 TE policy A to forward traffic with no service class value.

Figure 6 Uses SRv6 TE policy CBTS application scenario

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BFD for SRv6 TE policy

Echo BFD for SRv6 TE policy

If a candidate path of an SRv6 TE policy contains multiple SID lists, the SRv6 TE policy establishes a BFD session for each SID list to detect validity of the corresponding forwarding paths.

As shown in Figure 7, configure an SRv6 TE policy on Device A and use echo BFD to detect the SRv6 TE policy. The detection process is as follows:

1. The source node and sends BFD echo packets that each encapsulate a SID list of the SRv6 TE policy.

2. After the end-point node receives an BFD echo packet, it sends the BFD echo packet back to the source node by using the IPv6 routing table.

3. If the source node can receive the BFD echo packet within the detection timeout time, it determines the corresponding SID list (forwarding path) of the SRv6 TE policy is available. If no BFD echo packet is received, the device determines that the SID list is faulty. If all the SID lists for the primary path are faulty, BFD triggers a primary-to-backup path switchover.

Figure 7 Echo BFD for SRv6 TE policy procedure

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SBFD for SRv6 TE policy

An SRv6 TE policy cannot maintain its status by exchanging messages between devices. You can configure seamless BFD (SBFD) to verify the connectivity of an SRv6 TE policy to implement fast failover in milliseconds.

As shown in Figure 8, configure an SRv6 TE policy on Device A and use SBFD to detect the SRv6 TE policy. The detection process is as follows:

1. The source node (Device A, the initiator) and sends SBFD packets that encapsulate the SID lists of the primary and backup candidate paths of the SRv6 TE policy.

2. After the destination node (Device E, the reflector) receives an SBFD packets, it checks whether the remote discriminator carried the packet is the same as the local discriminator. If yes, the reflector sends the SBFD response packet to the initiator by using the IPv6 routing table. If no, the reflector drops the SBFD packet.

3. If the source node can receive the SBFD response within the detection timeout time, it determines the corresponding SID list (forwarding path) of the SRv6 TE policy is available. If no response is received, the device determines that the SID list is faulty. If all the SID lists for the primary path are faulty, SBFD triggers a primary-to-back path switchover.

Figure 8 SBFD for SRv6 TE policy procedure

NOTE:

Because SBFD responses are forwarded according to the IPv6 routing table lookup, all SBFD sessions for the SRv6 TE policies that have the same source and destination nodes use the same path to send responses. A failure of the SBFD response path will cause all the SBFD sessions to be down and packets cannot be forwarded through the SRv6 TE policies.

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SRv6 TE policy hot standby

If an SRv6 TE policy has multiple valid candidate paths, the device chooses the candidate path with the greatest preference value. If the chosen path fails, the SRv6 TE policy must select another candidate path. During path reselection, packet loss might occur and thus affect service continuity.

The SRv6 TE hot standby feature can address this issue. This feature takes the candidate path with the greatest preference value as the primary path and that with the second greatest preference value as the backup path in hot standby state. As shown in Figure 9, when the forwarding paths corresponding to all SID lists of the primary path fails, the standby path immediately takes over to minimize service interruption.

Figure 9 SRv6 TE policy hot standby

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You can configure both the hot standby and SBFD features for an SRv6 TE policy. Use SBFD to detect the availability of the primary and standby paths specified for hot standby. If all SID lists of the primary path become unavailable, the standby path takes over and a path recalculation is performed. The standby path becomes the new primary path, and a new standby path is selected. If both the primary and standby paths fail, the SRv6 TE policy will calculate new primary and standby paths.

SRv6 TE policy transit node protection

Protection path failure

The SID list of an SRv6 TE policy specifies the nodes or links that packets must traverse. As shown in Figure 10, node A forwards packets to node F through an SRv6 TE policy that includes node D in the forwarding path. The backup path must also contain node D. In this case, the backup path cannot provide protection for the forwarding path when node D fails.

Figure 10 Protection path failure

Transit node protection

To resolve the protection path failure caused by strict node constraints in an SRv6 TE policy, SRv6 TE FRR is introduced.

After SRv6 TE FRR is enabled, when a transit node of an SRv6 TE policy fails, the upstream node of the faulty node can take over to forward packets. The upstream node is called a proxy forwarding node.

After SRv6 TE FRR is enabled on a node, upon receiving a packet that contains an SRH and the SL in the SRH is greater than 0 (SL>0), the node will act as a proxy forwarding node in any of the following scenarios:

· The node does not find a matching forwarding entry in the IPv6 FIB.

· The next hop address of the packet is the destination address of the packet, and the outgoing interface for the destination address is in DOWN state.

· The matching local SRv6 SID is an END.X SID, and the outgoing interface for the END.X SID is in DOWN state.

· The outgoing interface in the matching route is NULL0.

A proxy forwarding node forwards packets as follows:

· Decrements the SL value in the SRH of a packet by 1.

· Copies the next SID to the DA field in the outer IPv6 header, so as to use the SID as the destination address of the packet.

· Looks up the forwarding table by the destination address and then forwards the packet.

In this way, the proxy forwarding node bypasses the fault node. This transit node failure protection technology is referred to as SRv6 TE FRR.

Figure 11 SRv6 TE FRR for transit node failure protection

As shown in Figure 11, after a packet is steered into an SRv6 TE policy, the packet is forwarded as instructed by the SID list {d, f}.

When node D fails, the node failure protection process is as follows:

1. Upstream node B detects that the nexthop of the packet is faulty, the nexthop address is the destination address of the packet, and the SL value is greater than 0. Therefore, node B performs the proxy forwarding behavior: Decrements the SL value by 1, copies the next SID to the DA field in the outer IPv6 header, and then forwards the packet according to the SID (destination address of the packet). Because the SL value is now 0, node B can remove the SRH and then search the corresponding table to forward the packet based on the destination address (f).

2. Node B forwards the packet as follows:

¡ If the route to node F is converged (the next hop in the route is node C), node B uses the converged shortest path to forward the packet to node C.

¡ If the route to node F is not converged (the primary next hop in the route is node D), node B uses the TI-LFA computed backup path to forward packet. The backup path's repair list is <c1>. Therefore, node B encapsulates an SRH to the packet to add backup path Segment List c1, and then forwards the packet over the backup path to node F.

Special processing on the source node

If source node A (ingress node) of the SRv6 TE policy detects the failure of node D (the first SID in the SID list is unreachable), node A then places the SRv6 TE policy to the down state. The device cannot forward packets through the SRv6 TE policy or trigger SRv6 TE FRR.

To resolve this issue, enable the bypass feature for the SRv6 TE policy on the source node. This feature enables the source node to generate a route that uses the first SID as the destination address and the NULL0 interface as the outgoing interface. The route ensures that the SRv6 TE policy is in up state when the first SID is unreachable, so as to trigger SRv6 TE FRR.

After node A triggers SRv6 TE FRR, node A decrements the SL value by 1, copies the next SID (f) to the DA field in the outer IPv6 header, and then forwards the packet to node B according to the SID (destination address of the packet).

When node B receives the packet, it processes the packet as follows:

· If the route to node F is converged (the next hop in the route is node C), node B uses the converged shortest path to forward the packet to node C.

· If the route to node F is not converged (the primary next hop in the route is node D), node B uses the TI-LFA computed backup path to forward the packet to node F.

SRv6 TE policy egress protection

This feature provides egress node protection in IP L3VPN over SRv6, EVPN L3VPN over SRv6, EVPN VPLS over SRv6, EVPN VPWS over SRv6, or public network IP over SRv6 networks where the public tunnel is an SRv6 TE policy tunnel.

SRv6 TE policy egress protection applies only to the dual homing scenario. To implement SRv6 TE policy egress protection, the egress node and the egress node's protection node must have the same forwarding entries.

IMPORTANT:

SRv6 TE policy egress protection is not supported in the dual homing scenario of the EVPN VPLS over SRv6 and EVPN VPWS over SRv6 networks if the redundancy mode is single active.

As shown in Figure 12, deploy an SRv6 TE policy between PE 1 and PE 3. PE 3 is the egress node (endpoint node) of the SRv6 TE policy. To improve forwarding reliability, configure PE 4 to protect PE 3.

Figure 12 SRv6 TE policy egress protection

End.M SID

In SRv6 TE policy egress protection, an End.M SID is used to protect the SRv6 SIDs in a specific locator. If an SRv6 SID advertised by the remote device (PE 3 in this example) is within the locator, the protection node (PE 4) uses the End.M SID to protect that SRv6 SID (remote SRv6 SID).

PE 4 takes different actions as instructed by an End.M SID in different network scenarios:

· IP L3VPN/EVPN L3VPN/Public network IP over SRv6 TE policy scenario

a. Removes the outer IPv6 header to obtain the remote SRv6 SID from the inner packet.

b. Searches the remote SRv6 SID and VPN instance/public instance mapping table to find the VPN instance/public instance mapped to the remote SRv6 SID.

c. Forwards the packet by looking up the routing table of the VPN instance/public instance.

· EVPN VPWS over SRv6 TE policy scenario

a. Removes the outer IPv6 header to obtain the remote SRv6 SID from the inner packet.

b. Searches the remote SRv6 SID and cross-connect mapping table to find the cross-connect mapped to the remote SRv6 SID.

c. Forwards the packet to the AC associated with the cross-connect.

In this scenario, the remote SRv6 SID must be an End.DX2 SID.

· EVPN VPLS over SRv6 TE policy scenario

a. Removes the outer IPv6 header to obtain the remote SRv6 SID from the inner packet.

b. Searches the remote SRv6 SID and VSI mapping table to find the VSI mapped to the remote SRv6 SID.

c. Forwards the packet according to the MAC address forwarding table of the VSI.

In this scenario, the remote SRv6 SID must be an End.DT2U SID.

Remote SRv6 SID

As shown in Figure 12, PE 4 receives a BGP route from PE 3. If the SRv6 SID in the BGP route is within the locator protected by the End.M SID on PE 4, PE 4 regards the SRv6 SID as a remote SRv6 SID and generates a mapping between the remote SRv6 SID and the VPN instance/public instance, cross-connect, or VSI.

When the adjacency between PE 4 and PE 3 breaks, PE 4 deletes the BGP route received from PE 3. As a result, the remote SRv6 SID and VPN instance/public instance/cross-connect/VSI mapping will be deleted, resulting in packet loss. To avoid this issue, you can configure the mappings deletion delay time on PE 4 to ensure that traffic is forwarded through PE 4 before PE 1 knows the PE 3 failure and computes a new forwarding path.

Route advertisement

The route advertisement procedure is similar in IP L3VPN, EVPN L3VPN, EVPN VPWS, EVPN VPLS, or public network IP over SRv6 TE policy egress protection scenarios. The following example describes the route advertisement in an IP L3VPN over SRv6 TE policy egress protection scenario.

As shown in Figure 12, the FRR path is generated on P 1 as follows:

1. PE 4 advertises the End.M SID and the protected locator to P 1 through an IPv6 IS-IS route. Meanwhile, PE 4 generates a local SID entry for the End.M SID.

2. Upon receiving the route that carries the End.M SID, P 1 generates an FRR route destined for the specified locator and the action for the route is pushing the End.M SID.

On PE 4, a <remote SRv6 SID, VPN instance > mapping entry is generated as follows:

1. Upon receiving the private route from CE 2, PE 3 encapsulates the route as a VPNv4 route and sends it to PE 4. The VPNv4 route carries the SRv6 SID, RT, and RD information.

2. After PE 4 receives the VPNv4 route, it obtains the SRv6 SID and the VPN instance. Then, PE 4 performs longest matching of the SRv6 SID against the locators protected by End.M SIDs. If a match is found, PE 4 uses the SRv6 SID as a remote SRv6 SID and generates a <remote SRv6 SID, VPN instance> mapping entry.

Packet forwarding

The packet forwarding procedure is similar in IP L3VPN, EVPN L3VPN, EVPN VPWS, EVPN VPLS, or public network IP over SRv6 TE policy egress protection scenarios. The following example describes the packet forwarding in an IP L3VPN over SRv6 TE policy egress protection scenario.

Figure 13 Data forwarding in SRv6 TE policy egress protection

As shown in Figure 13, typically traffic is forwarded along the CE 1-PE 1-P 1-PE 3-CE 2 path. When the egress node PE 3 fails, a packet is forwarded as follows:

1. P 1 detects that its next hop (PE 3) is unreachable and thus switches traffic to the FRR path. P 1 pushes the End.M SID into the IPv6 header of the packet and forwards the packet to PE 4.

2. PE 4 parses the packet and obtains the End.M SID. PE 4 queries the local SID table and takes actions as instructed by the End.M SID:

a. Removes the outer IPv6 header to obtain the remote SRv6 SID from the inner packet. (The remote SRv6 SID is A100::1 in this example)

b. Searches the remote SRv6 SID and VPN instance mapping table to find the VPN instance mapped to the remote SRv6 SID. (The VPN instance is VPN 1 in this example.)

c. Looks up the routing table of the VPN instance and forwards the packet to CE 2 according to the matching route.

Restrictions: Hardware compatibility with SRv6 TE policies

In standard system operating mode, this feature is available only for the following cards:

Card category	Cards
CSPEX	CSPEX-1802X, CSPEX-1802XA, CSPEX-2612XA, CSPEX-1812X-E, CSPEX-2304X-G, CSPEX-1502XA
SPE	RX-SPE200-E
CEPC	CEPC-CQ8L, CEPC-CQ8LA, CEPC-CQ8L1A, CEPC-CQ16L1

In SDN-WAN system operating mode, this feature is available only for the following cards:

Card category	Cards
CSPEX	CSPEX-1304X, CSPEX-1404X, CSPEX-1502X, CSPEX-1504X, CSPEX-1504XA, CSPEX-1602X, CSPEX-1602XA, CSPEX-1804X, CSPEX-1512X, CSPEX-1612X, CSPEX-1812X, CSPEX-1802X, CSPEX-1802XA, CSPEX-2612XA, CSPEX-1812X-E, CSPEX-2304X-G, CSPEX-1502XA
SPE	RX-SPE200, RX-SPE200-E
CEPC	CEPC-XP4LX, CEPC-XP24LX, CEPC-XP48RX, CEPC-CP4RX, CEPC-CP4RXA, CEPC-CP4RX-L, CEPC-CQ8L, CEPC-CQ8LA, CEPC-CQ8L1A, CEPC-CQ16L1
OAA	IM-NGFWX-IV

Restrictions and guidelines: SRv6 TE policy configuration

The SRv6 TE policy candidate paths do not support SID lists calculated by PCE. The PCE-related feature of SRv6 TE policy candidate path reoptimization is not supported.

SRv6 TE policy tasks at a glance

To configure an SRv6 TE policy, perform the following tasks:

1. Configuring an SRv6 TE policy and configure basic settings for the policy:

a. Creating an SRv6 TE policy

b. Configuring a PCEP session

This task is required when you use PCE to compute SID lists.

c. Configuring a candidate path and the SID lists of the path

d. (Optional.) Enabling strict SID encapsulation for SID lists

e. (Optional.) Configuring dynamic path calculation timers

f. (Optional.) Enabling the device to distribute SRv6 TE policy candidate path information to BGP-LS

g. (Optional.) Shutting down an SRv6 TE policy

2. (Optional.) Configuring BGP to advertise BGP IPv6 SR policy routes

a. Enabling BGP to advertise BGP IPv6 SR policy routes

b. Configuring BGP to redistribute BGP IPv6 SR policy routes

c. (Optional.) Enabling advertising BGP IPv6 SR policy routes to EBGP peers

d. (Optional.) Enabling Router ID filtering

e. (Optional.) Enabling validity check for BGP IPv6 SR policy routes

f. (Optional.) Configuring BGP to control BGP IPv6 SR policy route selection and advertisement

g. (Optional.) Maintaining BGP sessions

3. Configuring SRv6 TE policy traffic steering

4. (Optional.) Configuring the SRv6 TE policy encapsulation mode

5. (Optional.) Configuring high availability features for SRv6 TE policy

¡ Enabling SBFD for SRv6 TE policies

¡ Configuring the BFD echo packet mode for SRv6 TE policies

¡ Enabling hot standby for SRv6 TE policies

¡ Configuring path switchover and deletion delays for SRv6 TE policies

¡ Setting the delay time for bringing up SRv6 TE policies

¡ Configuring path connectivity verification for SRv6 TE policies

¡ Configuring SRv6 TE policy transit node protection

¡ Configuring SRv6 TE policy egress protection

¡ Configuring candidate path reoptimization for SRv6 TE policies

¡ Configuring flapping suppression for SRv6 TE policies

6. (Optional.) Configuring advanced settings for SRv6 TE policies

¡ Configuring the TTL processing mode of SRv6 TE policies

¡ Configuring SRv6 TE policy CBTS

¡ Configuring a rate limit for an SRv6 TE policy

¡ Enabling the device to drop traffic when an SRv6 TE policy becomes invalid

¡ Specifying the packet encapsulation type preferred in optimal route selection

7. (Optional.) Maintaining an SRv6 TE policy

¡ Configuring SRv6 TE policy resource usage alarm thresholds

¡ Enabling SRv6 TE policy logging

¡ Enabling SNMP notifications for SRv6 TE policies

¡ Configuring traffic forwarding statistics for SRv6 TE policies

Creating an SRv6 TE policy

Manually creating an SRv6 TE policy and configuring its attributes

About this task

An SRv6 TE policy is identified by a BSID, color, and end-point.

You can bind a BSID to the policy manually, or set only the color and end-point attributes of the policy so the system automatically assigns a BSID to the policy. If you use both methods, the manually bound BSID takes effect.

Restrictions and guidelines

The configured BSID must be on the locator specified for SRv6 TE policies in SRv6 TE view. Otherwise, the SRv6 TE policy cannot forward packets. For more information about the locator configuration, see "Configuring IPv6 Segment Routing."

Different SRv6 TE policies cannot have the same color and endpoint address combination.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Specify a locator for SRv6 TE.

srv6-policy locator locator-name

By default, no locator is specified for SRv6 TE.

5. Enter SRv6 TE policy view.

policy policy-name

6. Configure a BSID for the policy.

binding-sid ipv6 ipv6-address

7. Set the color and endpoint attributes.

color color-value end-point ipv6 ipv6-address

By default, the color and endpoint attributes of an SRv6 TE policy are not configured.

Automatically creating SRv6 TE policies by using ODN

About this task

When the device receives a BGP route, if the color extended attribute value of the BGP route is the same as the color value of an ODN template, the device automatically creates an SRv6 TE policy and two candidate paths for the policy. The automatically created candidate paths use preferences 100 and 200.

You can specify an IPv6 prefix list to filter BGP routes. The BGP routes permitted by the specified IPv6 prefix list can trigger ODN to create SRv6 TE policies. The BGP routes denied by the specified IPv6 prefix list cannot trigger ODN to create SRv6 TE policies.

An ODN-created SRv6 TE policy is deleted immediately when the matching BGP route is deleted. To avoid packet loss before the new forwarding path is computed, you can configure a proper deletion delay time for the SRv6 TE policy.

Restrictions and guidelines

You need to configure candidate paths for an ODN-created SRv6 TE policy.

· For the ODN-created candidate path preference 200, use affinity attributes or Flex-Algos to compute the SID lists for the candidate path.

· For the ODN-created candidate path preference 100, use PCE to compute the SID lists for the candidate path.

· Manually create candidate paths that use preferences other than 100 and 200, and then configure the SID lists for the candidate paths.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Specify a locator for SRv6 TE.

srv6-policy locator locator-name

By default, no locator is specified for SRv6 TE.

5. Create an ODN template and enter SRv6 TE ODN view.

on-demand color color-value

6. (Optional.) Configure the ODN SRv6 TE policy generation policy.

restrict prefix-list-name

By default, a BGP route can trigger ODN to create an SRv6 TE policy when the route's color attribute value is the same as the ODN color.

7. (Optional.) Configure the deletion delay time for ODN-created SRv6 TE policies.

delete-delay delay-time

By default, the deletion delay time for ODN-created SRv6 TE policies is 180000 milliseconds.

Configuring a PCEP session

Restrictions and guidelines

For more information about the PCEP commands, see MPLS TE commands in MPLS Command Reference.

Discovering PCEs

About this task

You can manually specify a PCE by using the pce static command on a PCC. A PCC sends PCEP connection requests to the discovered PCEs but does not accept requests from the PCEs.

Procedure

1. Enter system view.

system-view

2. Enter PCC view.

pce-client

3. Specify the IP address of the PCE.

pce static ip-address

Enabling the SRv6 capability for a PCC

Abou this task

To establish a PCEP session that supports SRv6, you need to enable the SRv6 capability on the devices at both sides of the PCEP session.

Procedure

1. Enter system view.

system-view

2. Configure the TE IPv6 router ID of the device.

te ipv6-router-id router-id

By default, the TE IPv6 router ID is not configured.

The TE IPv6 router ID is used to identify the source node in PCE requests. The TE IPv6 router ID of a device must be unique on the IPv6 network.

3. Enter PCC view.

pce-client

4. Enable the SRv6 capability for the PCC device.

pce capability segment-routing ipv6

By default, a PCC device does not have the SRv6 capability.

Configuring PCEP session parameters

About this task

This task allows you to configure parameters for a PCC to establish PCEP sessions to manually specified PCEs.

Procedure

1. Enter system view.

system-view

2. Enter PCC view.

pce-client

3. Set the path computation request timeout time.

pce request-timeout value

By default, the request timeout time is 10 seconds.

4. Set the PCEP session dead timer.

pce deadtimer value

By default, the PCEP session deadtimer is 120 seconds.

5. Set the keepalive interval for PCEP sessions.

pce keepalive interval

By default, the keepalive interval is 30 seconds.

6. Set the minimum acceptable keepalive interval and the maximum number of allowed unknown messages received from the PCE peer.

pce tolerance { min-keepalive value | max-unknown-messages value }

By default, the minimum acceptable keepalive interval is 10 seconds, and the maximum number of allowed unknown messages in a minute is 5.

7. Configure PCEP session authentication for a peer. Choose one option as needed:

¡ Configure the keychain authentication.

pce peer ip-address keychain keychain-name

¡ Configure the MD5 authentication.

pce peer ip-address md5 { cipher | plain } string

By default, PCEP session authentication is not configured.

For two devices to establish a PCEP session, you must configure the same authentication mode and specify the same key string on both devices.

Configuring a candidate path and the SID lists of the path

Restrictions and guidelines

Do not configure an SRv6 TE policy candidate path to use both manually configured SID lists and PCE-computed SID lists.

Configuring a candidate path to use manually configured SID lists

About this task

Before you specify a SID list for a candidate path, you need to create the SID list and add nodes to the SID list.

After you add nodes to a SID list, the system will sort the nodes in ascending order of node index. The node with the smallest index represents the next hop of the source node on the forwarding path.

To reduce the SRH cost, you can use four 32-bit G-SIDs to represent one normal 128-bit SRv6 SID. In a SID list, you can add a 128-bit SRv6 SID with a COC flavor, indicating that the next node of the current node is a 32-bit G-SID. For more information about G-SIDs, see "Configuring SRv6."

If multiple SRv6 TE policies have a common path, you can configure the common path as an SRv6 TE policy. When you configure the SRv6 TE policies, you can add the BSID of the common SRv6 TE policy to the SID lists of the SRv6 TE policies. In this way, you recurse the SRv6 TE policies to the common SRv6 TE policy, simplifying the SID list configuration.

Restrictions and guidelines

When you add a G-SID to the SID list, make sure the following requirements are met:

· The SRv6 SID previous to the G-SID is an End(COC32) SID or End.X(COC32) SID.

· The last SRv6 SID in the SID list does not carry the COC flavor. To meet this requirement, the penultimate node cannot be configured with an SRv6 SID by using the index index-number coc32 ipv6 command.

If the first SID in the SID list of an SRv6 TE policy is a BSID, note the following restrictions and guidelines:

· Nested SRv6 TE policy recursions are not supported, that is, the first SID in the SID list of the recursion SRv6 TE policy (the SRv6 TE policy with that BSID) cannot be a BSID.

· The first SID cannot be the BSID of this SRv6 TE policy itself.

· Do not configure path connectivity verification for this SRv6 TE policy.

· The BSID cannot be configured as a local BSID or a reverse BSID.

· The traffic statistics, BFD, and SBFD features of this SRv6 TE policy are not affected by the status of those features for the recursion SRv6 TE policy.

· The BFD/SBFD detection time of this SRv6 TE policy cannot be shorter than that of the recursion SRv6 TE policy.

· The path MTU of this SRv6 TE policy cannot be smaller than that of the recursion SRv6 TE policy.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Create a SID list and enter SID list view.

segment-list segment-list-name

5. Add a node to the SID list.

¡ Add a normal 128-bit SRv6 SID.

index index-number ipv6 ipv6-address [ verification ]

¡ Add a 128-bit SRv6 SID with the COC flavor, and specify the common prefix length for the next G_SID.

index index-number coc32 ipv6 ipv6-address common-prefix-length [ verification ]

6. Return to SRv6 TE view.

quit

7. Enter SRv6 TE policy view.

policy policy-name

8. Create and enter SRv6 TE policy candidate path view.

candidate-paths

9. Set the preference for a candidate path and enter SRv6 TE policy path preference view.

preference preference-value

By default, no candidate path preferences are set.

Each preference represents a candidate path.

10. Specify an explicit path for the candidate path.

explicit segment-list segment-list-name [ path-mtu mtu-value | weight weight-value ] *

A candidate path can have multiple SID lists.

Configuring a candidate path to create an SID list through affinity attribute-based path calculation

Creating a name-to-bit mapping for an affinity attribute

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Create the constraints mapping and enter its view.

affinity-map

5. Create a name-to-bit mapping for an affinity attribute.

name name bit-position bit-position-number

By default, no name-to-bit mapping is configured for an affinity attribute.

Configuring affinity attribute rules

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE policy view.

policy policy-name

5. Enter SRv6 TE policy candidate path view.

candidate-paths

6. Enter SRv6 TE policy candidate path preference view.

preference preference-value

Each preference represents a candidate path.

7. Create SRv6 TE policy constraints and enter constraints view.

constraints

8. Create and enter the affinity attribute view.

affinity

9. Configure affinity attribute rules.

¡ Configure the include-all affinity attribute rule and enter its view.

include-all

¡ Configure the include-any affinity attribute rule and enter its view.

include-any

¡ Configure the exclude-any affinity attribute rule and enter its view.

exclude-any

10. Specify an affinity attribute for an affinity attribute rule.

name name

By default, no affinity attribute is specified for an affinity attribute rule.

Configuring dynamic path calculation based on affinity attribute rule

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE policy view.

policy policy-name

5. Enter SRv6 TE policy candidate path view.

candidate-paths

6. Enter SRv6 TE policy candidate path preference view.

preference preference-value

Each preference represents a candidate path.

7. Enable dynamic path calculation and create and enter SRv6 TE policy path preference dynamic view.

dynamic

By default, dynamic path calculation is disabled.

8. Create a metric type and enter its view.

metric

9. Specify a metric.

type { hopcount | igp | latency | te }

By default, no metric is specified. The SRv6 TE policy cannot perform dynamic path calculation.

10. (Optional.) Configure the maximum number of SIDs in an SID list.

sid-limit limit-value

By defalut, the maximum number of SIDs in an SID list is 10 on the following cards:

Card category	Cards
CEPC	CEPC-CQ8L, CEPC-CQ8LA, CEPC-CQ8L1A, CEPC-CQ16L1
CSPEX	CSPEX-1802X, CSPEX-1802XA, CSPEX-2612XA, CSPEX-1812X-E, CSPEX-2304X-G, CSPEX-1502XA
SPE	RX-SPE200-E

By defalut, the maximum number of SIDs in an SID list is 5 on the following cards:

Card category	Cards
CEPC	CEPC-XP4LX, CEPC-XP24LX, CEPC-XP48RX, CEPC-CP4RX, CEPC-CP4RXA, CEPC-CP4RX-L
CSPEX	CSPEX-1304X, CSPEX-1404X, CSPEX-1502X, CSPEX-1504X, CSPEX-1504XA, CSPEX-1602X, CSPEX-1602XA, CSPEX-1804X, CSPEX-1512X, CSPEX-1612X, CSPEX-1812X
SPE	RX-SPE200
OAA	IM-NGFWX-IV

This command limits the number of SIDs in the SID lists for the candidate paths of an SRv6 TE policy during metric-based path calculation.

Configuring a candidate path to create an SID list through Flex-Algo-based path calculation

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE policy view.

policy policy-name

5. Enter SRv6 TE policy candidate path view.

candidate-paths

6. Enter SRv6 TE policy candidate path preference view.

preference preference-value

Each preference represents a candidate path.

7. Enable dynamic path calculation and create and enter SRv6 TE policy path preference dynamic view.

dynamic

By default, dynamic path calculation is disabled.

8. Return to SRv6 TE policy candidate path preference view.

quit

9. Create SRv6 TE policy constraints and enter constraints view.

constraints

10. Create the segment constraints and enter its view.

segments

11. Specify a Flex-Algo for an SRv6 TE policy.

sid-algorithm algorithm-id

By default, no Flex-Algo is associated with an SRv6 TE policy.

Configuring a candidate path to use PCE-computed SID lists

Prerequisites

Before you perform this task, configure a PCEP session first.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE policy view.

policy policy-name

5. Create and enter SRv6 TE policy candidate path view.

candidate-paths

6. Set the preference for a candidate path and enter SRv6 TE policy path preference view.

preference preference-value

By default, no candidate path preferences are set.

Each preference represents a candidate path.

7. Create and enter SRv6 TE policy path preference dynamic view.

dynamic

8. Enable a candidate path to use PCE to compute the SID lists.

pcep

By default, a candidate path does not use PCE to compute SID lists.

Configuring an ODN-created candidate path to create an SID list through affinity attribute-based path calculation

Creating a name-to-bit mapping for an affinity attribute

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Create the constraints mapping and enter its view.

affinity-map

5. Create a name-to-bit mapping for an affinity attribute.

name name bit-position bit-position-number

By default, no name-to-bit mapping is configured for an affinity attribute.

Configuring affinity attribute rules

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE ODN view.

on-demand color color-value

5. Enable dynamic path calculation and create and enter SRv6 TE ODN dynamic view.

dynamic

By default, dynamic path calculation is disabled.

6. Create the affinity attribute rule and enter its view.

affinity { include-all | include-any | exclude-any }

7. Specify an affinity attribute for an affinity attribute rule.

name name

By default, no affinity attribute is specified for an affinity attribute rule.

Configuring dynamic path calculation based on affinity attribute rule

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE ODN view.

on-demand color color-value

5. (Optional.) Configure the maximum depth for the SID label stack.

maximum-sid-depth value

By default, the maximum depth of the SID label stack is 10 on the following cards:

Card category	Cards
CEPC	CEPC-CQ8L, CEPC-CQ8LA, CEPC-CQ8L1A, CEPC-CQ16L1
CSPEX	CSPEX-1802X, CSPEX-1802XA, CSPEX-2612XA, CSPEX-1812X-E, CSPEX-2304X-G, CSPEX-1502XA
SPE	RX-SPE200-E

By default, the maximum depth of the SID label stack is 5 on the following cards:

Card category	Cards
CEPC	CEPC-XP4LX, CEPC-XP24LX, CEPC-XP48RX, CEPC-CP4RX, CEPC-CP4RXA, CEPC-CP4RX-L
CSPEX	CSPEX-1304X, CSPEX-1404X, CSPEX-1502X, CSPEX-1504X, CSPEX-1504XA, CSPEX-1602X, CSPEX-1602XA, CSPEX-1804X, CSPEX-1512X, CSPEX-1612X, CSPEX-1812X
SPE	RX-SPE200
OAA	IM-NGFWX-IV

To implement dynamic path calculation for ODN-generated SRv6 TE policies, use this command to control the number of SIDs in the SID lists for the candidate paths of the SRv6 TE policies.

6. Enable dynamic path calculation and create and enter SRv6 TE ODN dynamic view.

dynamic

By default, dynamic path calculation is disabled.

7. Create a metric type and enter its view.

metric

8. Specify a metric.

type { hopcount | igp | latency | te }

By default, no metric is specified. The SRv6 TE policy cannot perform dynamic path calculation.

Configuring an ODN-created candidate path to create an SID list through Flex-Algo-based path calculation

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE ODN view.

on-demand color color-value

5. (Optional.) Configure the maximum depth for the SID label stack.

maximum-sid-depth value

By default, the maximum depth of the SID label stack is 10 on the following cards:

Card category	Cards
CEPC	CEPC-CQ8L, CEPC-CQ8LA, CEPC-CQ8L1A, CEPC-CQ16L1
CSPEX	CSPEX-1802X, CSPEX-1802XA, CSPEX-2612XA, CSPEX-1812X-E, CSPEX-2304X-G, CSPEX-1502XA
SPE	RX-SPE200-E

By default, the maximum depth of the SID label stack is 5 on the following cards:

Card category	Cards
CEPC	CEPC-XP4LX, CEPC-XP24LX, CEPC-XP48RX, CEPC-CP4RX, CEPC-CP4RXA, CEPC-CP4RX-L
CSPEX	CSPEX-1304X, CSPEX-1404X, CSPEX-1502X, CSPEX-1504X, CSPEX-1504XA, CSPEX-1602X, CSPEX-1602XA, CSPEX-1804X, CSPEX-1512X, CSPEX-1612X, CSPEX-1812X
SPE	RX-SPE200
OAA	IM-NGFWX-IV

To implement dynamic path calculation for ODN-generated SRv6 TE policies, use this command to control the number of SIDs in the SID lists for the candidate paths of the SRv6 TE policies.

6. Enable dynamic path calculation and create and enter SRv6 TE ODN dynamic view.

dynamic

By default, dynamic path calculation is disabled.

7. Specify a Flex-Algo for an SRv6 TE policy.

sid-algorithm algorithm-id

By default, no Flex-Algo is associated with an SRv6 TE policy.

Configuring an ODN-created candidate path to use PCE-computed SID lists

Prerequisites

Before you perform this task, configure a PCEP session first.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE ODN view.

on-demand color color-value

5. Enter SRv6 TE ODN dynamic view.

dynamic

6. Enable a candidate path to use PCE to compute the SID lists.

pcep

By default, a candidate path does not use PCE to compute SID lists..

Configuring PCE delegation to create candidate paths and SID lists

About this task

After PCE delegation for an SRv6 TE policy is enabled, the PCC delegates the policy's candidate paths to a PCE. The PCC creates or updates candidate paths according to the creation or update requests received from the PCE.

When the device delegates only part of its SRv6 TE policies to a PCE, the PCE does not have complete SRv6 TE policy candidate path information to calculate global bandwidth information. You can enable the device to report information about the undelegated SRv6 TE policies to the PCE without using the PCE to compute candidate paths for the policies. This feature is referred to as the passive delegation report only feature.

Restrictions and guidelines

You can configure the PCE delegation and passive delegation report only features for all SRv6 TE policies globally in SRv6 TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

In SRv6 TE view, if you execute both the srv6-policy pce delegation enable command and the srv6-policy pce passive-delegate report-only enable command, the srv6-policy pce passive-delegate report-only enable command takes effect.

In SRv6 TE policy view, if you execute both the pce delegation command and the pce passive-delegate report-only command, the pce passive-delegate report-only command takes effect.

Prerequisites

Before you perform this task, configure a PCEP session first.

Configuring PCE delegation parameters

1. Enter system view.

system-view

2. Enter PCC view.

pce-client

3. Set the delegation priority of a PCE.

pce peer ip-address delegation-priority priority

By default, the delegation priority of a PCE is 65535.

A smaller value represents a higher priority.

4. Set the redelegation timeout interval.

pce redelegation-timeout value

By default, the redelegation timeout interval is 30 seconds.

5. Set the state timeout interval on the PCC.

pce state-timeout value

By default, the state timeout interval is 60 seconds.

6. Configure the PCC to retain PCE-updated LSP states.

pce retain lsp-state

By default, a PCC restores the original LSP states when the state timeout interval expires.

7. Configure the PCC to retain PCE-initiated LSPs.

pce retain initiated-lsp

By default, a PCC deletes PCE-initiated LSPs when the state timeout interval expires.

Enabling delegation

1. Enter system view.

system-view

2. Enter PCC view.

pce-client

3. Configure the PCEP device type as active stateful or passive stateful.

pcep type { active-stateful | passive-stateful }

By default, the PCEP device type is stateless.

4. Return to system view.

quit

5. Enter SRv6 view.

segment-routing ipv6

6. Enter SRv6 TE view.

traffic-engineering

7. Enable PCE delegation for SRv6 TE policies globally.

srv6-policy pce delegation enable

By default, PCE delegation for SRv6 TE policies is disabled globally.

8. Globally enable the PCC to report candidate information of an SRv6 TE policy to the PCE without delegating the policy to the PCE.

srv6-policy pce passive-delegate report-only enable

By default, this feature is disabled globally.

9. Enter SRv6 TE policy view.

policy policy-name

10. Enable PCE delegation for the SRv6 TE policy.

pce delegation { enable | disable }

By default, an SRv6 TE policy uses the PCE delegation setting configured in SRv6 TE view.

11. Enable the PCC to report candidate information of the SRv6 TE policy to the PCE without delegating the policy to the PCE.

pce passive-delegate report-only { enable | disable }

By default, an SRv6 TE policy uses the passive delegation report only setting configured in SRv6 TE view.

Enabling strict SID encapsulation for SID lists

About this task

The SID list of an SRv6 TE policy can be formed by prefix SIDs and adjacency SIDs. A prefix SID cannot uniquely identify a link. When the links in the network flap frequently, the forwarding paths of the SRv6 TE policy might change. To ensure stability of forwarding paths, perform this task to enable the SRv6 TE policy to include only adjacency SIDs in the calculated SID lists.

Prerequisites

Perform this task on the source node of an SRv6 TE policy.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enable strict SID encapsulation for SID lists.

¡ Execute the following commands in sequence to enable this feature in SRv6 TE policy path preference dynamic view.

policy policy-name

candidate-paths

preference preference-value

dynamic

strict-sid-only enable

¡ Execute the following commands in sequence to enable this feature in SRv6 TE ODN dynamic view.

on-demand color color-value

dynamic

strict-sid-only enable

By default, strict SID encapsulation is disabled for SID lists.

Configuring dynamic path calculation timers

About this task

Perform this task to avoid excessive resource consumption caused by frequent network changes.

If you specify the maximum-interval, minimum-interval, and incremental-interval settings for the command, the following situations will occur:

· For the first path calculation triggered for the SRv6 TE policy, the minimum-interval setting applies.

· For the nth (n > 1) path calculation triggered for the SRv6 TE policy, the device adds a value of incremental-interval × 2n-2 based on the minimum-interval setting. The total value does not exceed the maximum-interval setting.

If the value of minimum-interval + incremental-interval × 2n-2 is larger than or equal to the value of maximum-interval, the device uses the conservative keyword and SRv6 TE policy flapping condition to adjust the path calculation intervals:

· If the conservative keyword is specified:

¡ If SRv6 TE policy flappings occur, the maximum-interval setting applies.

¡ If no SRv6 TE policy flappings occur, the maximum interval applies for once, and then the minimum interval applies.

· If the conservative keyword is not specified:

¡ If SRv6 TE policy flappings occur, the maximum interval applies for three consecutive times, and then the minimum interval applies.

¡ If no SRv6 TE policy flappings occur, the maximum interval applies for once, and then the minimum interval applies.

Restrictions and guidelines

The value of the minimum-interval or incremental-interval argument cannot be greater than the maximum-interval argument.

To increase path calculation frequency for faster path calculation, configure a fixed interval.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing

3. Enter SRv6 TE view.

traffic-engineering

4. Configure the dynamic path calculation timers.

srv6-policy calc-schedule-interval { maximum-interval [ minimum-interval [ incremental-interval [ conservative ] ] ] | millisecond interval }

By default, the maximum, minimum, and incremental intervals for dynamic path calculation are 5 seconds, 50 milliseconds, and 200 milliseconds, respectively.

Enabling the device to distribute SRv6 TE policy candidate path information to BGP-LS

About this task

After this feature is enabled, the device distributes SRv6 TE policy candidate path information to BGP-LS. BGP-LS advertises the SRv6 TE policy candidate path information in routes to meet application requirements.

Prerequisites

Before you configure this feature, enable the device to exchange LS information with the related peer or peer group. For more information about the LS exchange capability, see the BGP LS configuration in Layer 3—IP Routing Configuration Guide.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enable the device to distribute SRv6 TE policy candidate path information to BGP-LS.

distribute bgp-ls

By default, the device cannot distribute SRv6 TE policy candidate path information to BGP-LS

Shutting down an SRv6 TE policy

About this task

This feature controls the administrative state of an SRv6 TE policy.

If multiple SRv6 TE policies exist on the device, you can shut down unnecessary SRv6 TE policies to prevent them from affecting traffic forwarding.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE policy view.

policy policy-name

5. Shut down the SRv6 TE policy.

shutdown

By default, an SRv6 TE policy is not administratively shut down.

Configuring BGP to advertise BGP IPv6 SR policy routes

Restrictions and guidelines for BGP IPv6 SR policy routes advertisement

For more information about BGP commands, see Layer 3—IP Routing Commands.

Enabling BGP to advertise BGP IPv6 SR policy routes

1. Enter system view.

system-view

2. Configure a global router ID.

router id router-id

By default, no global router ID is configured.

3. Enable a BGP instance and enter its view.

bgp as-number [ instance instance-name ]

By default, BGP is disabled and no BGP instances exist.

4. Configure a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } as-number as-number

5. Create the BGP IPv6 SR policy address family and enter its view.

address-family ipv6 sr-policy

6. Enable BGP to exchange BGP IPv6 SR policy routing information with the peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } enable

By default, the device cannot exchange BGP IPv6 SR policy routing information with a peer or peer group.

Configuring BGP to redistribute BGP IPv6 SR policy routes

About this task

After you configure BGP to redistribute BGP IPv6 SR policy routes, the system will redistribute the local BGP IPv6 SR policy routes to the BGP routing table and advertise the routes to peers. Then, the peers can forward traffic based on the SRv6 TE policy.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP IPv6 SR policy address family view.

address-family ipv6 sr-policy

4. Enable BGP to redistribute routes from SRv6 TE policies.

import-route sr-policy

By default, BGP does not redistribute BGP IPv6 SR policy routes.

Enabling advertising BGP IPv6 SR policy routes to EBGP peers

About this task

By default, BGP IPv6 SR policy routes are advertised among IBGP peers. To advertise BGP IPv6 SR policy routes to EBGP peers, you must perform this task to enable the advertisement capability.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP IPv6 SR policy address family view.

address-family ipv6 sr-policy

4. Enable advertising BGP IPv6 SR policy routes to EBGP peers.

advertise ebgp enable

By default, BGP IPv6 SR policy routes are not advertised to EBGP peers.

Enabling Router ID filtering

About this task

For the device to process only part of the received BGP IPv6 SR policy routes, you can perform this task to enable filtering the routes by Router ID.

This command enables the device to check the Route Target attribute of a received BGP IPv6 SR policy route.

· If the Route Target attribute contains the Router ID of the local device, the device accepts the route and generates an SRv6 TE policy accordingly.

· If the Route Target attribute does not contain the Router ID of the local device, the device processes the route as follows:

¡ If the bgp-rib-only keyword is not specified in the command, the device drops the route.

¡ If the bgp-rib-only keyword is specified in the command, the device accepts the route but does not generate the corresponding SRv6 TE policy.

When the controller advertises a BGP IPv6 SR policy route to the source node, the transit nodes between the controller and the source node only need to forward the BGP IPv6 SR policy route. They do not need to generate the SRv6 TE policy. In this case, you can execute the router-id filter bgp-rib-only command on the transit nodes. Then, when a transit node receives a BGP IPv6 SR policy route, it forwards the route even if the route's Route Target attribute does not contain the Router ID of the local device. Meanwhile, it does not generate an SRv6 TE policy in order to not affect packet forwarding.

Restrictions and guidelines

To use Router ID filtering, make sure you add Route Target attributes to BGP IPv6 SR policy routes properly by using routing policy or other methods. Otherwise, Router ID filtering might learn or drop BGP IPv6 SR policy routes incorrectly.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP IPv6 SR policy address family view.

address-family ipv6 sr-policy

4. Enable Router ID filtering.

router-id filter [ bgp-rib-only ]

By default, Router ID filtering is disabled.

Enabling validity check for BGP IPv6 SR policy routes

About this task

After validity check is enabled for BGP IPv6 SR policy routes, the device determines that a BGP IPv6 SR policy route is invalid and will not select the route if the route does not contain the IPv4 address format RT extended community attribute or the NO_ADVERTISE community attribute.

You can configure this feature on the RR in networks where the controller and the RR establish BGP peer relationship and the RR establishes BGP peer relationship with the source nodes of multiple SRv6 TE policies.

The RR checks whether the BGP IPv6 SR policy routes issued by the controller carry the IPv4 address format RT attribute or the NO_ADVERTISE attribute. If yes, the RR accepts the routes and reflects the routes that do not carry the NO_ADVERTISE attribute to the source nodes of the SRv6 TE policies.

On the source nodes, you can use the router-id filter command to enable BGP IPv6 SR policy route filtering by router ID. After a source node receives a BGP IPv6 SR policy route, it compares the local router ID with the IPv4 address in the RT attribute of the route. If they are the same, the source node accepts the route. If they are different, the source node drops the route.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP IPv6 SR policy address family view.

address-family ipv6 sr-policy

4. Enable validity check for BGP IPv6 SR policy routes.

validation-check enable

By default, validity check for BGP IPv6 SR policy routes is disabled. The device does not check the validity of the BGP IPv6 SR policy routes received from peers or peer groups.

Configuring BGP to control BGP IPv6 SR policy route selection and advertisement

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP IPv6 SR policy address family view.

address-family ipv6 sr-policy

4. Specify the local router as the next hop for routes sent to a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } next-hop-local

By default, BGP sets the local router as the next hop for all routes sent to an EBGP peer or peer group. BGP does not set the local router as the next hop for routes sent to an IBGP peer or peer group.

5. Configure the default local preference value.

default local-preference value

By default, the local preference is 100.

6. Allow a local AS number to exist in the AS_PATH attribute of routes from a peer or peer group, and to set the number of times the local AS number can appear.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } allow-as-loop [ number ]

By default, the local AS number is not allowed to exist in the AS_PATH attribute of routes from a peer or peer group.

7. Specify a preferred value for routes received from a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } preferred-value value

By default, the preferred value is 0 for routes received from a peer or peer group.

8. Set the maximum number of routes that can be received from a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } route-limit prefix-number [ { alert-only | discard | reconnect reconnect-time } | percentage-value ] *

By default, the number of routes that can be received from a peer or peer group is not limited.

9. Configure the device as a route reflector and specify a peer or peer group as a client.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } reflect-client

By default, neither the route reflector nor the client is configured.

10. Enable the route reflector to change the attributes of routes to be reflected.

reflect change-path-attribute

By default, a route reflector cannot change the attributes of routes to be reflected.

11. Specify an IPv6 prefix list to filter routes received from or advertised to a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } prefix-list ipv6-prefix-list-name { export | import }

By default, no prefix list based filtering is configured.

12. Apply a routing policy to routes incoming from or outgoing to a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } route-policy route-policy-name { export | import }

By default, no routing policy is applied to routes incoming from or outgoing to a peer or peer group.

13. Specify an AS path list to filter routes incoming from or outgoing to a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } as-path-acl { as-path-acl-number | as-path-acl-name } { export | import }

By default, no AS path list is specified for filtering.

14. Advertise the COMMUNITY attribute to a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } advertise-community

By default, BGP does not advertise the COMMUNITY attribute to any peers or peer groups.

15. Advertise the extended community attribute to a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } advertise-ext-community

By default, BGP does not advertise the extended community attribute to any peers or peer groups.

16. Advertise the Large Community attribute to a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } advertise-large-community

By default, BGP does not advertise the Large Community attribute any peers or peer groups.

17. Assign a peer or peer group a high priority in BGP route selection.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } high-priority

By default, a peer or peer group does not have a high priority in BGP route selection.

18. Configure the route selection delay time.

route-select delay delay-value

By default, the route selection delay time is 0 seconds, which means no route selection delay.

Maintaining BGP sessions

To maintain BGP sessions, execute the following commands in user view:

· Reset BGP sessions for the BGP IPv6 SR policy address family.

reset bgp [ instance instance-name ] { as-number | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] | all | external | group group-name | internal } ipv6 sr-policy

· Soft-reset BGP sessions for the BGP IPv6 SR policy address family.

refresh bgp [ instance instance-name ] { ipv6-address | ipv4-address [ mask-length ] [ prefix-length ] | all | external | group group-name | internal } { export | import } ipv6 sr-policy

Configuring SRv6 TE policy traffic steering

Configuring the SRv6 TE policy traffic steering mode

Prerequisites

To use color-based traffic steering, you need to add the color extended community to IPv6 unicast routes by using routing policy or other methods. For information about the routing policy configuration, see Layer 3—IP Routing Configuration Guide.

To use tunnel policy-based traffic steering, you need to configure a bound tunnel, preferred tunnel, or load sharing tunnel policy that uses an SRv6 TE policy. For more information about the tunnel policy configuration, see MPLS Configuration Guide.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Configure the traffic steering mode for SRv6 TE policies.

sr-policy steering [ disable | policy-based ]

By default, the device steering data packets to SRv6 TE policies based on colors of the packets.

If you specify the policy-based keyword, the device steers traffic based on the bound policy, color, and tunnel load sharing policy in a descending order of priority.

Configuring color-based traffic steering

About this task

To steer traffic to an SRv6 TE policy based on colors, you can configure a color extended community for routes that do not carry a color extended community in the following methods:

· Configure a routing policy to add a color value to routes.

· Configure a default color value.

The color value specified in the routing policy is preferred.

Restrictions and guidelines

The default color value applies only to the VPN routes or public network routes learned from a remote PE.

The default color value is used only for SRv6 TE policy traffic steering. It does not used in route advertisement.

Configuring a routing policy to add a color value to routes

1. Enter system view.

system-view

2. Enter routing policy node view.

route-policy route-policy-name { deny | permit } node node-number

3. Set the color extended community attribute for BGP routes.

apply extcommunity color color [ additive ]

By default, no color extended community attribute is set for BGP routes.

4. Return to system view.

quit

5. Enter BGP instance view.

bgp as-number [ instance instance-name ]

6. Enter a BGP address family view as needed:

¡ Enter BGP IPv4 unicast address family view.

address-family ipv4 [ unicast ]

¡ Enter BGP IPv6 unicast address family view

address-family ipv6 [ unicast ]

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

¡ Enter BGP EVPN address family view.

address-family l2vpn evpn

7. Apply the routing policy to filter routes advertised to or received from a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } route-policy route-policy-name { export | import }

By default, no routing policy is applied to a peer or peer group.

Configuring a default color value for VPN routes

1. Enter system view.

system-view

2. Enter VPN instance view.

ip vpn-instance vpn-instance-name [ index vpn-index ]

3. Enter IPv4 address family view or IPv6 address family view of the VPN instance.

¡ Enter VPN instance IPv4 address family view.

address-family ipv4

¡ Enter VPN instance IPv6 address family view.

address-family ipv6

4. Configure a default color value for L3VPN route recursion to an SRv6 TE policy.

default-color color-value [ evpn ]

By default, no default color is configured for L3VPN route recursion to an SRv6 TE policy.

Configuring a default color value for public network routes

1. Enter system view.

system-view

2. Enter pubic instance view.

ip public-instance

3. Enter public instance IPv4 or IPv6 address family view.

¡ Enter public instance IPv4 address family view

address-family ipv4

¡ Enter public instance IPv6 address family view.

address-family ipv6

4. Configure a default color value for public network route recursion to an SRv6 TE policy.

default-color color-value

By default, no default color value is configured for public network route recursion to an SRv6 TE policy.

Configuring tunnel policy-based traffic steering

Configuring a tunnel policy

1. Enter system view.

system-view

2. Create a tunnel policy and enter tunnel policy view.

tunnel-policy tunnel-policy-name [ default ]

3. Configure the tunnel policy. Choose the following tasks as needed:

¡ Specify an SRv6 TE policy to be bound with the specified destination IPv6 address.

binding-destination dest-ipv6-address srv6-policy { name policy-name | end-point ipv6 ipv6-address color color-value } [ ignore-destination-check ] [ down-switch ]

By default, no SRv6 TE policy is specified for a tunnel policy.

¡ Specify an SRv6 TE policy as a preferred tunnel of the tunnel policy.

preferred-path srv6-policy name srv6-policy-name

By default, no preferred tunnel is specified for a tunnel policy.

¡ Configuring SRv6 TE policy load sharing for the tunnel policy.

select-seq srv6-policy load-balance-number number

By default, no load sharing tunnel policy is configured.

For more information about the tunnel policy commands, see MPLS Command Reference.

Specifying the tunnel policy for a VPN instance

1. Enter system view.

system-view

2. Enter a VPN instance view as needed.

¡ Enter VPN instance view.

ip vpn-instance vpn-instance-name

¡ Execute the following commands in sequence to enter VPN instance IPv4 address family view:

ip vpn-instance vpn-instance-name

address-family ipv4

¡ Execute the following commands in sequence to enter VPN instance IPv6 address family view:

ip vpn-instance vpn-instance-name

address-family ipv6

3. Specify a tunnel policy for the VPN instance.

tnl-policy tunnel-policy-name

By default, no tunnel policy is specified for a VPN instance.

For more information about this command, see MPLS L3VPN commands in MPLS Command Reference.

Specifying the tunnel policy for a PW

1. Enter system view.

system-view

2. Enter cross-connect group view.

xconnect-group group-name

3. Enter cross-connect view.

connection connection-name

4. Create an EVPN PW and specify a tunnel policy for this PW.

evpn local-service-id local-service-id remote-service-id remote-service-id tunnel-policy tunnel-policy-name

Specifying the tunnel policy for an EVPN instance

1. Enter system view.

system-view

2. Enter VSI view.

vsi vsi-name

3. Enter EVPN instance view.

evpn encapsulation srv6

4. Specify a tunnel policy for the EVPN instance.

tunnel-policy tunnel-policy-name

By default, no tunnel policy is specified for an EVPN instance.

For more information about this command, see EVPN Command Reference.

Configuring DSCP-based traffic steering

About this task

Each SRv6 TE policy in an SRv6 TE policy group has a different color attribute value. By configuring color-to-DSCP mappings for an SRv6 TE policy group, you associate DSCP values to SRv6 TE policies. This allows IPv6 packets containing a specific DSCP value to be steered to the corresponding SRv6 TE policy for further forwarding.

You can create an SRv6 TE policy group in the following methods:

· Manual creation at the CLI

This method requires manually configuring the destination node address of the SRv6 TE policy group.

· Automatic creation by ODN

¡ The policy group uses the BGP route's next hop address as the end-point address and the ODN template's color value as the color attribute value.

¡ The device will assign the smallest ID that are not in use to the SRv6 TE policy group.

Restrictions and guidelines

You can map the color values of only valid SRv6 TE policies to DSCP values.

You can configure color-to-DSCP mappings separately for the IPv4 address family and IPv6 address family. For a specific address family, a DSCP value can be mapped to only one color value.

Use the color match dscp default command to specify the default SRv6 TE policy for an address family. If no SRv6 TE policy in an SRv6 TE policy group matches a specific DSCP value, the default SRv6 TE policy is used to forward packets containing the DSCP value. Only one default SRv6 TE policy can be specified for an address family.

When the device receives an IPv4 or IPv6 packet that does not match any color-to-DSCP mapping, the device selects a valid SRv6 TE policy for the packet in the following order:

1. The default SRv6 TE policy specified for the same address family as the packet.

2. The default SRv6 TE policy specified for the other address family.

3. The SRv6 TE policy mapped to the smallest DSCP value in the same address family as the packet.

4. The SRv6 TE policy mapped to the smallest DSCP value in the other address family.

Manually creating an SRv6 TE policy group

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Create an SRv6 TE policy group and enter its view.

policy-group group-id

5. Configure the endpoint IPv6 address for the SRv6 TE policy group.

end-point ipv6 ipv6-address

By default, no endpoint IPv6 address is configured for the SRv6 TE policy group.

The SRv6 TE policy associated with each color value in the SRv6 TE policy group must use the same endpoint IPv6 address as the SRv6 TE policy group.

6. (Optional.) Create the color value for the SRv6 TE policy group.

group-color color-value

By default, the color value is not configured for an SRv6 TE policy group.

7. Create color-to-DSCP mappings for the SRv6 TE policy group.

color color-value match dscp { ipv4 | ipv6 } dscp-value-list

color color-value match dscp { ipv4 | ipv6 } default

By default, no color-to-DSCP mappings are created for the SRv6 TE policy group.

DSCP-based traffic steering cannot function if no color-to-DSCP mappings are created.

Automatically creating an SRv6 TE policy group by ODN

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Create an ODN template for creating SRv6 TE policy groups and enter SRv6 TE ODN policy group view.

on-demand-group color color-value

5. (Optional.) Configure the description of the SRv6 TE policy group ODN template.

description text

By default, the description of the SRv6 TE policy group ODN template is not configured.

6. Create the DSCP forward type and enter its view.

forward-type dscp

7. Create color-to-DSCP mappings for the SRv6 TE policy group ODN template.

color color-value match dscp { ipv4 | ipv6 } dscp-value-list

color color-value match dscp { ipv4 | ipv6 } default

By default, no color-to-DSCP mappings are created for the SRv6 TE policy group ODN template.

This command is required to implement DSCP-based traffic steering.

Steering traffic to an SRv6 TE policy group

1. Enter system view.

system-view

2. Configure traffic steering to an SRv6 TE policy group.

a. Create a tunnel policy and enter tunnel policy view.

tunnel-policy tunnel-policy-name [ default ]

b. Bind the SRv6 TE policy group to a destination IP address.

binding-destination dest-ip-address sr-policy group sr-policy-group-id [ ignore-destination-check ] [ down-switch ]

By default, a tunnel policy does not bind any SRv6 TE policy group to a destination IP address.

For more information about the command, see tunnel policy commands in MPLS Command Reference.

c. Configure color-based traffic steering.

For more information, see "Configuring color-based traffic steering."

Specify a color value as the color extended community attribute of BGP routes in the routing policy according to the creation method of the SRv6 TE policy group.

- If the SRv6 TE policy group is manually created, the specified color value must be the color value of the SRv6 TE policy group.

- If the SRv6 TE policy group is automatically created by ODN, the specified color value must be the color value of the ODN template.

Configuring 802.1p-based traffic steering

About this task

Each SRv6 TE policy in an SRv6 TE policy group has a different color attribute value. By configuring color-to-802.1p mappings for an SRv6 TE policy group, you associate 802.1p values to SRv6 TE policies. This allows packets containing a specific 802.1p value to be steered to the corresponding SRv6 TE policy for further forwarding.

Hardware and feature compatibility

This feature is available only for the following cards:

Card category	Cards
CEPC	CEPC-CQ8L, CEPC-CQ8LA, CEPC-CQ8L1A, CEPC-CQ16L1
CSPEX	CSPEX-1802X, CSPEX-1802XA, CSPEX-2612XA, CSPEX-1812X-E, CSPEX-2304X-G, CSPEX-1502XA
SPE	RX-SPE200-E

Restrictions and guidelines

You can map the color values of only valid SRv6 TE policies to 802.1p values. For an SRv6 TE policy group, an 802.1p value can be mapped to only one color value.

Use the color match dot1p default command to specify the default SRv6 TE policy for an SRv6 TE policy group. If no SRv6 TE policy in an SRv6 TE policy group matches a specific 802.1p value, the default SRv6 TE policy is used to forward packets containing the 802.1p value. Only one default SRv6 TE policy can be specified for an SRv6 TE policy group.

When the device receives a packet that does not match any color-to-802.1p mapping, the device selects a valid SRv6 TE policy for the packet in the following order:

1. The default SRv6 TE policy.

2. The SRv6 TE policy mapped to the smallest 802.1p value.

The device performs an IPv6 routing table lookup to forward the packet that does not match any of the previous SRv6 TE policies.

Manually creating an SRv6 TE policy group

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Create an SRv6 TE policy group and enter its view.

policy-group group-id

5. Configure the endpoint IPv6 address for the SRv6 TE policy group.

end-point ipv6 ipv6-address

By default, no endpoint IPv6 address is configured for the SRv6 TE policy group.

The SRv6 TE policy associated with each color value in the SRv6 TE policy group must use the same endpoint IPv6 address as the SRv6 TE policy group.

6. (Optional.) Create the color value for the SRv6 TE policy group.

group-color color-value

By default, the color value is not configured for an SRv6 TE policy group.

7. Specify the Dot1p forward type for the SRv6 TE policy group.

forward-type dot1p

By default, DSCP-based traffic steering is used for packets that match an SRv6 TE policy group.

8. Create color-to-802.1p mappings for the SRv6 TE policy group.

color color-value match dot1p dot1p-value-list

color color-value match dot1p default

By default, no color-to-802.1p mappings are created for an SRv6 TE policy group.

Steering traffic to an SRv6 TE policy group

1. Enter system view.

system-view

2. Configure traffic steering to an SRv6 TE policy group.

a. Create a tunnel policy and enter its view.

tunnel-policy tunnel-policy-name [ default ]

b. Bind the SRv6 TE policy group to a destination IP address.

binding-destination dest-ipv6-address srv6-policy group srv6-policy-group-id [ ignore-destination-check ] [ down-switch ]

By default, a tunnel policy does not bind any SRv6 TE policy group to a destination IP address.

For more information about the command, see tunnel policy commands in MPLS Command Reference.

c. Configure color-based traffic steering.

For more information, see "Configuring color-based traffic steering."

Specify the color value of the SRv6 TE policy group as the color extended community attribute of BGP routes in the routing policy

Configuring static route-based traffic steering

Restrictions and guidelines

In the IP public network over SRv6 scenario, after you configure this feature, execute the route-replicate command in public instance IPv4/IPv6 address family view to replicate the routes of the specified VPN instance to the public network, so the public network can use the VPN routes to forward user traffic.

Procedure

1. Enter system view.

system-view

2. Configure static-route based traffic steering to an SRv6 TE policy.

¡ Configure an IPv4 static route for steering matching traffic to an SRv6 TE policy.

Public network:

ip route-static dest-address { mask-length | mask } srv6-policy { color color-value end-point ipv6 ipv6-address | name policy-name } [ preference preference ] [ tag tag-value ] [ description text ]

VPN:

ip route-static vpn-instance s-vpn-instance-name dest-address { mask-length | mask } srv6-policy { color color-value end-point ipv6 ipv6-address | name policy-name } [ preference preference ] [ tag tag-value ] [ description text ]

By default, no IPv4 static routes are configured.

For more information about this command, see static routing configuration in Layer 3—IP Routing Configuration Guide.

¡ Configure an IPv6 static route for steering matching traffic to an SRv6 TE policy.

Public network:

ipv6 route-static ipv6-address prefix-length srv6-policy { color color-value end-point ipv6 ipv6-address | name policy-name } [ preference preference ] [ tag tag-value ] [ description text ]

VPN:

ipv6 route-static vpn-instance s-vpn-instance-name ipv6-address prefix-length srv6-policy { color color-value end-point ipv6 ipv6-address | name policy-name } [ preference preference ] [ tag tag-value ] [ description text ]

By default, no IPv6 static routes are configured.

For more information about this command, see IPv6 static routing configuration in Layer 3—IP Routing Configuration Guide.

Configuring QoS policy-based traffic steering

About this task

When some public IPv6 flows are congested, you can configure traffic classification to identify the flows and redirect the traffic to SRv6 TE policies to resolve the congestion. Traffic redirection to SRv6 TE policies is based on endpoint and color. If traffic cannot match the redirect rule or the redirect SRv6 TE policy fails, the traffic cannot be forwarded through an SRv6 TE policy but through normal IPv6 forwarding.

Restrictions and guidelines

For more information about QoS policy commands, see ACL and QoS Command Reference.

Procedure

1. Define a traffic class:

a. Enter system view.

system-view

b. Create a traffic class and enter traffic class view.

traffic classifier classifier-name [ operator { and | or } ]

c. Configure a match criterion.

if-match [ not ] match-criteria

By default, no match criterion is configured.

For more information, see the if-match command in ACL and QoS Command Reference.

2. Define a traffic behavior:

a. Create a traffic behavior and enter traffic behavior view.

traffic behavior behavior-name

b. Redirect the matching traffic to an SRv6 TE policy.

redirect srv6-policy endpoint color [ { sid | vpnsid } sid ]

By default, no traffic behavior is configured.

3. Define and apply a QoS policy:

a. Create a QoS policy and enter QoS policy view.

qos policy policy-name

b. Associate a traffic class with a traffic behavior to create a class-behavior association in the QoS policy.

classifier classifier-name behavior behavior-name

By default, a traffic class is not associated with a traffic behavior.

c. Return to system view.

quit

d. Apply the QoS policy.

For more information, see QoS policy configuration in ACL and QoS Configuration Guide.

By default, no QoS policy is applied.

Configuring Flowspec-based traffic steering

Creating and activating an IPv6 Flowspec rule

1. Enter system view.

system-view

2. Create an IPv6 Flowspec rule and enter IPv6 Flowspec rule view.

flow-route flowroute-name ipv6

3. Configure a match criterion.

if-match match-criteria

By default, no match criterion is configured.

4. Configure actions. Choose one option as needed.

¡ Redirect packets to an SRv6 TE policy.

apply redirect next-hop ipv6-address color color [ sid sid-value ]

¡ Redirect packets to an SRv6 BE tunnel.

apply redirect next-hop ipv6-address sid sid-value [ prefix-length prefix-length ]

By default, no action is configured.

5. Commit match criteria and actions.

commit

By default, match criteria and actions are not committed.

Applying the IPv6 Flowspec rule to the public network

1. Enter system view.

system-view

2. Enter Flowspec view.

flowspec

3. Create a Flowspec IPv6 address family for the public network and enter its view.

address-family ipv6

4. Apply the created IPv6 Flowspec rule to the public network. Choose one option as needed:

¡ Apply an IPv6 Flowspec rule.

flow-route flowroute-name

By default, no IPv6 Flowspec rule is applied to the public network.

¡ Apply an IPv6 Flowspec rule and associate it with a Flowspec interface group.

flow-route flowroute-name flow-interface-group group-id

By default, no IPv6 Flowspec rule is applied to the public network, and no Flowspec interface group is associated with an IPv6 Flowspec rule.

Applying the IPv6 Flowspec rule to a VPN instance

1. Enter system view.

system-view

2. Configure a VPN instance.

a. Create a VPN instance and enter VPN instance view.

ip vpn-instance vpn-instance-name

b. Configure an RD for the VPN instance.

route-distinguisher route-distinguisher

By default, no RD is configured for a VPN instance.

c. Configure route targets for the VPN instance.

vpn-target { vpn-target&<1-8> [ both | export-extcommunity | import-extcommunity ] }

By default, no route targets are configured.

For more information about the ip vpn-instance, route-distinguisher, and vpn-target commands, see MPLS L3VPN commands in MPLS Command Reference.

3. Enter the IPv6 Flowspec address family view of the VPN instance.

address-family ipv6 flowspec

4. Configure an RD for the IPv6 Flowspec address family.

route-distinguisher route-distinguisher

By default, no RD is configured for the IPv6 Flowspec address family.

5. Configure route targets for the IPv6 Flowspec address family.

vpn-target vpn-target&<1-8> [ both | export-extcommunity | import-extcommunity ]

By default, no route targets are configured for the IPv6 Flowspec address family.

The route targets configured must be the same as the route targets configured previously for the VPN instance.

6. Execute the quit command twice to return to system view.

7. Enter Flowspec view.

flowspec

8. Create a Flowspec IPv6 address family and associate the address family with the VPN instance.

address-family ipv6 vpn-instance vpn-instance-name

9. Apply the created IPv6 Flowspec rule to the Flowspec IPv6 VPN instance address family. Choose one option as needed:

¡ Apply an IPv6 Flowspec rule.

flow-route flowroute-name

By default, no IPv6 Flowspec rule is applied to a Flowspec IPv6 VPN instance address family.

¡ Apply an IPv6 Flowspec rule and associate it with a Flowspec interface group.

flow-route flowroute-name flow-interface-group group-id

By default, no IPv6 Flowspec rule is applied to the public network, and no Flowspec interface group is associated with an IPv6 Flowspec rule.

Enabling BGP to distribute IPv6 Flowspec rules

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP IPv6 Flowspec address family view, BGP-VPN IPv6 Flowspec address family view, or BGP VPNv6 Flowspec address family view:

¡ Enter BGP IPv6 Flowspec address family view to advertise public network IPv6 Flowspec rules.

address-family ipv6 flowspec

¡ Execute the following commands in sequence to enter BGP-VPN IPv6 Flowspec address family view to advertise private network IPv6 Flowspec rules:

ip vpn-instance vpn-instance-name

address-family ipv6 flowspec

¡ Enter BGP VPNv6 Flowspec address family view to advertise VPNv6 Flowspec rules.

address-family vpnv6 flowspec

4. Enable BGP Flowspec peers to exchange routing information.

peer { group-name | ipv6-address [ mask-length ] | ipv6-address [ prefix-length ] } enable

By default, BGP Flowspec peers cannot exchange routing information.

Enabling automatic route advertisement for an SRv6 TE policy

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE policy view.

policy policy-name

5. Enable automatic route advertisement for the SRv6 TE policy.

autoroute enable [ isis | ospfv3 ]

By default, automatic route advertisement is disabled for an SRv6 TE policy.

6. Configure an autoroute metric for the SRv6 TE policy.

autoroute metric { absolute value | relative value }

By default, the autoroute metric of an SRv6 TE policy equals its IGP metric.

7. Return to system view.

quit

8. Include the SRv6 TE policy in IGP computation:

¡ Execute the following commands in sequence to enable automatic route advertisement for IS-IS SRv6 TE policies.

isis [ process-id ] [ vpn-instance vpn-instance-name ]

address-family ipv6 [ unicast ]

srv6-policy autoroute enable [ level-1 | level-2 ]

¡ Execute the following commands in sequence to enable automatic route advertisement for OSPFv3 SRv6 TE policies.

ospfv3 [ process-id | vpn-instance vpn-instance-name ] *

srv6-policy autoroute enable

By default, automatic route advertisement for SRv6 TE policies is disabled for IPv6 IS-IS and OSPFv3.

Configuring the SRv6 TE policy encapsulation mode

About this task

If the traffic steering mode is BSID, packets whose destination IPv6 address is the same as the BSID of an SRv6 TE policy will be forwarded by the SRv6 TE policy. In this case, the device needs to encapsulate the SID list of the SRv6 TE policy into the packets. The following encapsulation modes are available:

· Encaps—Normal encapsulation mode. It adds a new IPv6 header and an SRH to the original packets. All SIDs in the SID list of the SRv6 TE policy are encapsulated in the SRH. The destination IPv6 address in the new IPv6 header is the first SID in the SID list of the SRv6 TE policy. The source IPv6 address is the IPv6 address specified by using the encapsulation source-address command.

· Encaps.Red—Reduced mode of normal encapsulation. It adds a new IPv6 header and an SRH to the original packets. The first SID in the SID list of the SRv6 TE policy is not encapsulated in the SRH to reduce the SRH length. All other SIDs in the SID list are encapsulated in the SRH. The destination IPv6 address in the new IPv6 header is the first SID in the SID list of the SRv6 TE policy. The source IPv6 address is the IPv6 address specified by using the encapsulation source-address command.

If the traffic steering mode is BSID and the SRv6 SID of the ingress node is an End.X SID, the device does not encapsulate the End.X SID into the SRH by default.

To obtain complete SRv6 forwarding path information from the SRH of packets, you can configure the device to encapsulate the local End.X SID in the SRH.

Restrictions and guidelines

You can configure the encapsulation mode for all SRv6 TE policies globally in SRv6 TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

In SRv6 TE view or SRv6 TE policy view, if you configure both the reduced mode and the include local-end.x mode for normal encapsualtion of packets, the include local-end.x mode takes effect.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Configure the Encaps.Red encapsulation mode globally for all SRv6 TE policies.

srv6-policy encapsulation-mode encaps reduced

By default, an SRv6 TE policy uses the Encaps encapsulation mode.

5. Enable the device to include the local End.X SID in the SRH of the packets forwarded by SRv6 TE policies with a normal encapsulation mode.

srv6-policy encapsulation-mode encaps include local-end.x

By default, the device does not include the local End.X SID in the SRH of the packets forwarded by SRv6 TE policies.

6. Enter SRv6 TE policy view.

policy policy-name

7. Specify the Encaps.Red encapsulation mode for the SRv6 TE policy.

encapsulation-mode encaps reduced [ disable ]

By default, the encapsulation mode is not configured for an SRv6 TE policy, and the encapsulation mode configured in SRv6 TE view applies.

8. Configure local End.X SID encapsulation in the SRH of the packets forwarded by the SRv6 TE policy with a normal encapsulation mode.

encapsulation-mode encaps include local-end.x [ disable ]

By default, local End.X SID encapsulation is not configured for an SRv6 TE policy, and the local End.X SID encapsulation setting configured in SRv6 TE view applies.

Enabling SBFD for SRv6 TE policies

About this task

To use SBFD to detect an SRv6 TE policy, the device needs to encapsulate the SID list of the SRv6 TE policy for the SBFD packets. The following encapsulation modes are available:

· Encaps—Normal encapsulation mode. It adds a new IPv6 header and an SRH to the original packets.

¡ The destination IPv6 address in the new IPv6 header is the first SID in the SID list of the SRv6 TE policy. The source IPv6 address is the IPv6 address specified by using the encapsulation source-address command.

¡ All SIDs in the SID list of the SRv6 TE policy are encapsulated in the SRH.

· Insert—Insertion mode. It inserts an SRH after the original IPv6 header.

¡ The destination IPv6 address in the original IPv6 header is changed to the first SID in the SID list of the SRv6 TE policy. The source IPv6 address is the IPv6 address specified by using the encapsulation source-address command.

¡ All SIDs in the SID list of the SRv6 TE policy are encapsulated in the SRH.

Restrictions and guidelines

You can enable SBFD for all SRv6 TE policies globally in SRv6 TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

The remote discriminator specified on the device (initiator) must be the same as that specified in the sbfd local-discriminator command on the reflector. Otherwise, the reflector will not send responses to the initiator.

The device supports the echo packet mode BFD and the SBFD for an SRv6 TE policy. If both modes are configured for the same SRv6 TE policy, the SBFD takes effect.

Procedure

1. Enter system view.

system-view

2. Configure the encapsulation mode as Encap for SBFD packets.

bfd srv6-encapsulation-mode encap

By default, the SRv6 TE policy encapsulation mode for SBFD packets is the Insert mode.

3. Configure the source IPv6 address used by the initiator to send SBFD packets.

sbfd source-ipv6 ipv6-address

By default, no source IPv6 address is configured for SBFD packets.

4. Enter SRv6 view.

segment-routing ipv6

5. Enter SRv6 TE view.

traffic-engineering

6. Enable SBFD for all SRv6 TE policies and configure the SBFD session parameters.

srv6-policy sbfd [ remote remote-id ] [ template template-name ] [ backup-template backup-template-name ]

By default, SBFD is disabled for all SRv6 TE policies.

7. (Optional.) Enable BFD session down events to trigger SRv6 TE policy path reselection globally.

srv6-policy bfd trigger path-down enable

By default, the feature for triggering SRv6 TE policy path reselection with BFD session down events is disabled globally.

8. (Optional.) Configure the timer that delays reporting the first BFD or SBFD session establishment failure to an SRv6 TE policy.

srv6-policy bfd first-fail-timer seconds

By default, the timer that delays reporting the first BFD or SBFD session establishment failure to an SRv6 TE policy is 60 seconds.

9. Enter SRv6 TE policy view.

policy policy-name

10. Configure SBFD for the SRv6 TE policy.

sbfd { disable | enable [ remote remote-id ] [ template template-name ] [ backup-template backup-template-name ] [ oam-sid sid ] [ encaps | insert ] }

By default, SBFD is not configured for an SRv6 TE policy.

If you do not specify the encaps or insert keyword, the encapsulation mode configured by the bfd srv6-encapsulation-mode encap command applies.

After the reverse-path keyword is specified, BFD packets can be encapsulated only in Insert mode. The encaps keyword does not take effect.

11. (Optional.) Configure BFD session down events to trigger SRv6 TE policy path reselection.

bfd trigger path-down { disable | enable }

By default, the feature for triggering the SRv6 TE policy path reselection by BFD session down events is not configured. The configuration in SRv6 TE view applies.

Configuring the BFD echo packet mode for SRv6 TE policies

About this task

By default, the returning BFD echo packets used for SRv6 TE policy connectivity detection are forwarded based on the IP forwarding path. If an intermediate device fails, the returning packets will be discarded, the BFD session will go down, and the SID list will be mistakenly considered as faulty.

To resolve this issue, you can enable the returning BFD packets to be forwarded based on the specified SID list to ensure connectivity as follows:

1. Configure a reverse BSID in SID list view on the ingress node, and configure a local BSID with the same value in SID list view on the egress node.

2. When the ingress node forwards a BFD packet, it encapsulates an SID list in the SRH. In addition, it encapsulates the reverse BSID associated with the SID list to the SL=1 location.

3. When the egress node receives the BFD packet, it compares the SID at the SL=1 location in the SRH with the configured local BSID. If the values are the same, the egress node encapsulates an SRH for the returning BFD packet and forwards the packet based on the SID list associated with the local BSID.

To use echo BFD to detect an SRv6 TE policy, the device needs to encapsulate the SID list of the SRv6 TE policy for the BFD packets. The following encapsulation modes are available:

· Encaps—Normal encapsulation mode. It adds a new IPv6 header and an SRH to the original packets.

¡ All SIDs in the SID list of the SRv6 TE policy are encapsulated in the SRH.

· Insert—Insertion mode. It inserts an SRH after the original IPv6 header.

¡ All SIDs in the SID list of the SRv6 TE policy are encapsulated in the SRH.

Restrctions and guidelines

You can configure the echo packet mode BFD for all SRv6 TE policies globally in SRv6 TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

The device supports the echo packet mode BFD and the SBFD for an SRv6 TE policy. If both modes are configured for the same SRv6 TE policy, the SBFD takes effect.

Procedure

1. Enter system view.

system-view

2. Configure the encapsulation mode as Encap for BFD packets.

bfd srv6-encapsulation-mode encap

By default, the SRv6 TE policy encapsulation mode for BFD packets is the Insert mode.

3. Enter SRv6 view.

segment-routing ipv6

4. Enter SRv6 TE view.

traffic-engineering

5. Enable echo packet mode BFD for all SRv6 TE policies and configure the BFD session parameters.

srv6-policy bfd echo source-ipv6 ipv6-address [ template template-name ] [ backup-template backup-template-name ] [ reverse-path reverse-binding-sid ]

By default, the echo packet mode BFD is disabled for all SRv6 TE policies.

6. (Optional.) Enable BFD session down events to trigger SRv6 TE policy path reselection globally.

srv6-policy bfd trigger path-down enable

By default, the feature for triggering SRv6 TE policy path reselection with BFD session down events is disabled globally.

7. (Optional.) Configure the local BSID and reverse BSID for an SID list.

a. Enter SID list view.

segment-list segment-list-name

b. Configure the local BSID.

local-binding-sid ipv6 ipv6-address

c. Configure the reverse BSID.

reverse-binding-sid ipv6 ipv6-address

d. Return to SRv6 TE view.

quit

The specified local BSID or reverse BSID cannot be the same as the BSID of the SRv6 TE policy. If they are the same, the SID list becomes invalid and cannot be used to forward packets.

The specified local BSID or reverse BSID must be within the static length of the locator specified in SRv6 TE view. If this condition is not met, the SID list associated with the BSID cannot be used to forward packets.

8. (Optional.) Configure the timer that delays reporting the first BFD or SBFD session establishment failure to an SRv6 TE policy.

srv6-policy bfd first-fail-timer seconds

By default, the timer that delays reporting the first BFD or SBFD session establishment failure to an SRv6 TE policy is 60 seconds.

9. Enter SRv6 TE policy view.

policy policy-name

10. Configure the echo packet mode BFD for the SRv6 TE policy.

bfd echo { disable | enable [ source-ipv6 ipv6-address ] [ template template-name ] [ backup-template backup-template-name ] [ oam-sid sid ] [ encaps | insert ] [ reverse-path reverse-binding-sid ] }

By default, the echo packet mode BFD is not configured for an SRv6 TE policy. An SRv6 TE policy uses the echo BFD settings configured in SRv6 TE view.

If you do not specify the encaps or insert keyword, the encapsulation mode configured by the bfd srv6-encapsulation-mode encap command applies.

11. (Optional.) Configure BFD session down events to trigger SRv6 TE policy path reselection.

bfd trigger path-down { disable | enable }

By default, the feature for triggering SRv6 TE policy path reselection by BFD session down events is not configured. The configuration in SRv6 TE view applies.

12. Specify the local BSID and reverse BSID for BFD detection of an SID list.

a. Enter SRv6 TE policy candidate path view.

candidate-paths

b. Enter SRv6 TE policy path preference view.

preference preference-value

Each preference represents a candidate path.

c. Specify the local BSID and reverse BSID for BFD detection of an SID list.

explicit segment-list segment-list-name [ local-binding-sid ipv6 ipv6-address | reverse-binding-sid ipv6 ipv6-address ] *

For the local BSID:

- The specified BSID cannot be the same as the BSID configured with the local-binding-sid command for the SID list.

- The specified BSID takes precedence over the BSID configured with the local-binding-sid command for the SID list.

For the reverse BSID:

- The specified BSID cannot be the same as the BSID configured with the reverse-binding-sid command for the SID list.

- The specified BSID takes precedence over the BSID configured with the reverse-binding-sid command for the SID list.

Enabling hot standby for SRv6 TE policies

Restrictions and guidelines

You can enable hot standby for all SRv6 TE policies globally in SRv6 TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enable hot standby for all SRv6 TE policies.

srv6-policy backup hot-standby enable

By default, hot standby is disabled for all SRv6 TE policies.

5. Enter SRv6 TE policy view.

policy policy-name

6. Configure hot standby for the SRv6 TE policy.

backup hot-standby { disable | enable }

By default, hot standby is not configured for an SRv6 TE policy, and the hot standby configuration in SRv6 TE view applies.

Configuring path switchover and deletion delays for SRv6 TE policies

About this task

The switchover delay and deletion delay mechanism is used to avoid traffic forwarding failure during a forwarding path (SID list) switchover.

When updating an SRv6 TE policy forwarding path, the device first establishes the new forwarding path before it deletes the old one. During the new path setup process, the device uses the old path to forward traffic until the switchover delay timer expires. When the switchover delay timer expires, the device switches traffic to the new path. The old path is deleted when the deletion delay timer expires.

To apply the switchover delay and deletion delay, the old and new forwarding paths of the SRv6 TE policy must both be up. When the old forwarding path goes down, traffic is switched to the new path immediately without waiting for the switchover delay time.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Configure the switchover delay time and deletion delay time for the SRv6 TE policy forwarding path.

srv6-policy switch-delay switch-delay-time delete-delay delete-delay-time

By default, the switchover delay time and deletion delay time for the SRv6 TE policy forwarding path is 5000 milliseconds and 20000 milliseconds, respectively.

Setting the delay time for bringing up SRv6 TE policies

About this task

After an SRv6 TE policy recovers from a fault, the device waits for the delay time before bringing up the SRv6 TE policy. This is to ensure that the fault is completely removed so as to avoid packet loss caused by SRv6 TE policy flapping.

After this command is executed, the device starts different delay timers for an SRv6 TE policy according to the BFD/SBFD configuration for the SRv6 TE policy.

· If BFD/SBFD is not enabled, the device starts an LSP delay timer when the SID list state changes from Down to Up.

· If BFD is enabled, the device starts a BFD delay timer when the BFD session state changes from Down to Up.

· If SBFD is enabled, the device starts an SBFD delay timer when the SBFD session state changes from Down to Up.

Restrictions and guidelines

To view the BFD/SBFD configuration, SID list state, and SBFD session state, execute the display segment-routing ipv6 te policy command.

Set a proper SRv6 TE policy up delay time according to your network conditions. A very long delay time will cause an SRv6 TE policy to be unable to process user traffic for a long time.

You can set the delay time for all SRv6 TE policies globally in SR TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

If you execute this command for multiple times, the most recent configuration takes effect. A new delay time setting does not apply to the SRv6 TE policies that are already in a policy-up delay process.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Set the policy-up delay time for all SRv6 TE policies.

srv6-policy up-delay delay-time

By default, the device does not delay bringing up SRv6 TE policies.

5. Enter SRv6 TE policy view.

policy policy-name

6. Set the policy-up delay time for the SRv6 TE policy.

up-delay delay-time

By default, no policy-up delay time is set for an SRv6 TE policy and the policy-up delay time set in SR TE view applies.

Configuring path connectivity verification for SRv6 TE policies

About this task

Typically, the controller deploys the SID list of an SRv6 TE policy. Without BFD configured, the first node cannot immediately detect path failures in the SRv6 TE policy. It only changes the SID list of the SRv6 TE policy as instructed by the controller that completes path recalculation upon detecting a topology change. If the controller or the link to the controller fails, the first node will be unable to detect failures and change SID lists, resulting in traffic loss.

For fast traffic switchover and high availability, you can enable path connectivity verification for the first node of the SRv6 TE policy. This feature enables the first node to collect network topology information, and verify all SID lists in the SRv6 TE policy as follows:

· If all SRv6 SIDs exist in the topology and the associated locator prefixes are routable, the SID list is valid.

· If any SRv6 SIDs do not exist in the topology or any of the associated locator prefixes are not routable, the SID list is invalid.

Upon detecting an invalid SID list (SID list failure), the first node changes paths as follows:

1. If the valid candidate paths of the SRv6 TE policy contain multiple SID lists, and one of the SID list fails, traffic is distributed to other valid SID lists.

2. If the SRv6 TE policy has valid primary and backup candidate paths, and all SID lists for the primary candidate path fail, traffic is distributed to the backup candidate path.

3. If all valid candidate paths of the SRv6 TE policy fail, the SRv6 TE policy is faulty and an associated protection action is taken (for example, MPLS L3VPN FRR).

Restrictions and guidelines

You must configure this feature on the first node of the SRv6 TE policy. Even if you configure this feature on the controller and the controller deploys the BGP IPv6 SR policy route to the device, you still need to configure this feature on the first node of the SRv6 TE policy.

You can configure SRv6 TE policy path connectivity verification in both SRv6 TE view and SRv6 TE policy view. The configuration in SRv6 TE policy view takes precedence over the configuration in SRv6 TE view. If path connectivity verification is not configured for an SRv6 TE policy, the configuration in SRv6 TE applies.

The first node must have all SRv6 SIDs and routes in the IGP domain to detect their status through the following settings:

· Enable the IGP domain to forward routing information through IPv6 IS-IS.

· Configure the distribute link-state command in IS-IS view for the first node to report link status.

After path connectivity verification is enabled for an SRv6 TE policy, the device verifies the validity of all SIDs in the SID list. If the SID list contains an inter-AS SID (for example, the BGP Peer SID allocated by BGP EPE) or contains the BSID of another SRv6 TE policy, the path connectivity verification will fail. This is because a BSID or BGP Peer SID cannot be flooded in the IGP topology.

To resolve this issue, you can execute the following commands to configure the path connectivity verification only verifies the validity of specific SIDs:

· Use the index command to specify the verification keyword for the SIDs to be verified. Do not specify this keyword for a BSID or BGP EPE SID in the SID list.

· Specify the specified-sid keyword when you execute the path verification command in SRv6 TE policy view or the srv6-policy path verification enable command in SRv6 TE view.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enable path connectivity verification for all SRv6 TE policies.

srv6-policy path verification [ specified-sid ] enable

By default, path connectivity verification is disabled for all SRv6 TE policies.

5. Enter SRv6 TE policy view.

policy policy-name

6. Configure path connectivity verification for an SRv6 TE policy.

path verification { disable | [ specified-sid ] enable }

By default, path connectivity verification is not configured for an SRv6 TE policy. The setting configured in SRv6 TE view applies.

Configuring SRv6 TE policy transit node protection

About this task

The transit node protection technology is referred to as SRv6 TE FRR. After SRv6 TE FRR is enabled, when a transit node of an SRv6 TE policy fails, the upstream node of the faulty node can take over to forward packets. The upstream node is called a proxy forwarding node that bypasses the faulty transit node to implement node failure protection.

Hardware and feature compatibility

This feature is available only for the following cards:

Card category	Cards
CEPC	CEPC-CQ8L, CEPC-CQ8LA, CEPC-CQ8L1A, CEPC-CQ16L1
CSPEX	CSPEX-1802X, CSPEX-1802XA, CSPEX-2612XA, CSPEX-1812X-E, CSPEX-2304X-G, CSPEX-1502XA
SPE	RX-SPE200-E

Restrictions and guidelines

In a complex network, any node might act as a transit node. As a best practice to improve the whole network security, enable SRv6 TE FRR on all nodes.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enable SRv6 TE FRR.

sr-te frr enable

4. Enter SRv6 TE view.

traffic-engineering

5. Enter SRv6 TE policy view.

policy policy-name

6. Enable the bypass feature for the SRv6 TE policy.

bypass enable

By default, the SRv6 TE policy bypass feature is disabled.

Execute this command only on the source node.

Configuring SRv6 TE policy egress protection

Restrictions and guidelines for SRv6 TE policy egress protection configuration

The IM-NGFWX-IV card does not support this feature.

To configure SRv6 TE policy egress protection, all nodes that the packets will traverse must support SRv6.

Configuring an End.M SID

Restrictions and guidelines

Perform this task on protection node for the egress node.

For more information about the commands used in this task, see IPv6 Segment Routing commands in Segment Routing Command Reference.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Create a locator and enter SRv6 locator view.

locator locator-name [ ipv6-prefix ipv6-address prefix-length [ args args-length | static static-length ] * ]

4. Configure an End.M SID and specify the locator to be protected by the End.M SID.

opcode opcode end-m mirror-locator ipv6-address prefix-length

Enabling egress protection

About this task

This task enables the SRv6 node to compute a backup path (mirror FRR path) for the egress node based on the End.M SID carried in a received IPv6 IS-IS or OSPFv3 route. When the egress node fails, the transit node can forward traffic to the node that protects the egress node according to the End.M SID.

In an egress protection scenario, the transit node deletes the mirror FRR path after completing route convergence. If the deletion occurs before the ingress node switches traffic back from the mirror FRR path, the traffic will be dropped because of no mirror FRR path.

To resolve this issue, you can configure a proper mirror FRR deletion delay time on the transit node to delay the deletion of the mirror FRR route. So, packets can be forwarded over the mirror FRR path before the ingress finishes the path switchover.

Enabling IS-IS egress protection

1. Enter system view.

system-view

2. Enter IS-IS view.

isis [ process-id ] [ vpn-instance vpn-instance-name ]

3. Enter IS-IS IPv6 address family view.

address-family ipv6 [ unicast ]

4. Enable IS-IS egress protection.

fast-reroute mirror enable

By default, IS-IS egress protection is disabled.

5. (Optional.) Configure the mirror FRR deletion delay time.

fast-reroute mirror delete-delay delete-delay-time

By default, the mirror FRR deletion delay time is 60 seconds.

Enabling OSPFv3 egress protection

1. Enter system view.

system-view

2. Enter OSPFv3 view.

ospfv3 [ process-id | vpn-instance vpn-instance-name ] *

3. Enable OSPFv3 egress protection.

fast-reroute mirror enable

By default, OSPFv3 egress protection is disabled.

4. (Optional.) Configure the mirror FRR deletion delay time.

fast-reroute mirror delete-delay delete-delay-time

By default, the mirror FRR deletion delay time is 60 seconds.

Configuring the deletion delay time for remote SRv6 SID mappings with VPN instances/public instance/cross-connects/VSIs

About this task

In an egress protection scenario, if the egress node and the egress node's protection node are disconnected, the protection node will delete the BGP routes received from the egress node. The remote SRv6 SID and VPN instance/public instance/cross-connect/VSI mappings will then be deleted as a result. To avoid this issue, you can configure the mappings deletion delay time on the protection node. This ensures that traffic is forwarded through the protection node before the ingress detects the egress failure and computes a new forwarding path.

Restrictions and guidelines

Perform this task on the protection node for the egress node.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Configure the deletion delay time for remote SRv6 SID mappings with VPN instances/public instance/cross-connects/VSIs.

mirror remote-sid delete-delay delete-delay-time

By default, the deletion delay time for remote SRv6 SID and VPN instance/public instance/cross-connect/VSI mappings is 60 seconds.

Configuring candidate path reoptimization for SRv6 TE policies

About this task

This feature enables the PCE to periodically compute paths and notify the PCC to update path information, so that SRv6 TE policies can use the optimal path to establish the candidate path.

For example, an SRv6 TE policy uses a path other than the optimal path to establish the candidate path because the optimal path does not have sufficient link bandwidth. This feature enables the SRv6 TE policy to switch the candidate path to the optimal path when the link bandwidth becomes sufficient.

Restrictions and guidelines

You can configure candidate path reoptimization for all SRv6 TE policies globally in SRv6 TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view

traffic-engineering

4. Enable candidate path reoptimization for SRv6 TE policies globally.

srv6-policy reoptimization [ frequency seconds ]

By default, candidate path reoptimization is disabled for SRv6 TE policies globally.

5. Enter SRv6 TE policy view.

policy policy-name

6. Configure candidate path reoptimization for the SRv6 TE policy.

reoptimization { disable | enable [ frequency seconds ] }

By default, candidate path reoptimization is not configured for an SRv6 TE policy, and the configuration in SRv6 TE view applies.

7. Return to user view.

quit

8. Immediately reoptimize all SRv6 TE policies enabled with candidate path reoptimization.

srv6-policy immediate-reoptimization

Configuring flapping suppression for SRv6 TE policies

About this task

After SRv6 TE policy flapping suppression is enabled, the device starts a counter for an SRv6 TE policy to count the SID list flapping events for the policy.

· If the state of a SID list changes from down to up within the flapping detection interval, an SID list flapping event occurs, and the flapping count increases by 1.

· If the time for a SID list to change from down to up is longer than the resumption interval, the flapping counter is cleared.

· If the flapping count exceeds the flapping suppression threshold, the SRv6 TE policy enters flapping suppression state. In this state, the SRv6 TE policy does not update the SID list state but keep the SID list in down state, and the flapping counter is not cleared.

· When the suppression state lasts for the resumption interval, the device ends the suppression state of the SRv6 TE policy and clears the flapping counter.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view

traffic-engineering

4. Disable flapping suppression for SRv6 TE policies globally.

srv6-policy suppress-flapping disable

By default, candidate path reoptimization is disabled for SRv6 TE policies globally.

5. Enter SRv6 TE policy view.

policy policy-name

6. Configure flapping suppression parameters for the SRv6 TE policy.

srv6-policy suppress-flapping { detect-interval detect-interval | threshold threshold | resume-interval resume-interval } *

By default, the SRv6 TE policy flapping detection interval is 60 seconds, the flapping suppression threshold is 10, and the flapping suppression resumption interval is 120 seconds.

Configuring the TTL processing mode of SRv6 TE policies

About this task

An SRv6 TE policy used as a public tunnel supports the following TTL processing modes:

· Uniform—When the ingress node adds a new IPv6 header to an IP packet, it copies the TTL value of the original IP packet to the Hop Limit field of the new IPv6 header. Each node on the SRv6 TE policy forwarding path decreases the Hop Limit value in the new IPv6 header by 1. The node that de-encapsulates the packet copies the remaining Hop Limit value back to the original IP packet when it removes the new IPv6 header. The TTL value can reflect how many hops the packet has traversed in the public network. The tracert facility can show the real path along which the packet has traveled.

· Pipe—When the ingress node adds a new IPv6 header to an IP packet, it does not copy the TTL value of the original IP packet to the Hop Limit field of the new IPv6 header. It sets the Hop Limit value in the new IPv6 header to 255. Each node on the SRv6 TE policy forwarding path decreases the Hop Limit value in the new IPv6 header by 1. The node that de-encapsulates the packet does not change the IPv6 Hop Limit value according to the remaining Hop Limit value in the new IPv6 header. Therefore, the public network nodes are invisible to user networks, and the tracert facility cannot show the real path in the public network.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Configure the TTL processing mode of SRv6 TE policies.

ttl-mode { pipe | uniform }

By default, the TTL processing mode of SRv6 TE policies is pipe.

Configuring SRv6 TE policy CBTS

Prerequisites

Before configuring CBTS, you must create QoS traffic behaviors to mark the MPLS TE service class values for packets. For more information, see QoS configuration in ACL and QoS Configuration Guide.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE policy view.

policy policy-name

5. Set a service class value for the SRv6 TE policy.

service-class service-class-value

By default, no service class value is set for an SRv6 TE policy. The service class value is 255 with the lowest forwarding priority.

Configuring a rate limit for an SRv6 TE policy

About this task

When the rate of the packets forwarded by an SRv6 TE policy exceeds the rate limit, the device drops the packets that exceed the rate limit.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enter SRv6 TE policy view.

policy policy-name

5. Set a rate limit for the SRv6 TE policy.

rate-limit kbps

By default, no rate limit is set for an SRv6 TE policy.

Enabling the device to drop traffic when an SRv6 TE policy becomes invalid

About this task

Enable this feature for an SRv6 TE policy if you want to use only the SRv6 TE policy to forward traffic.

By default, if all forwarding paths of an SRv6 TE policy become invalid, the device forwards the packets through IPv6 routing table lookup based on the packet destination IPv6 addresses.

After you execute the drop-upon-invalid enable command, the device drops the packets if all forwarding paths of the SRv6 TE policy become invalid.

Restrictions and guidelines

The feature does not take effect in the following cases:

· BSID request failed or BSID conflicted for the SRv6 TE policy. To view the BSID request state, see the Request state field in the display segment-routing ipv6 te policy command output.

· The SRv6 TE policy is invalid. To check the SRv6 TE policy validity, see the Forwarding index field in the display segment-routing ipv6 te policy command output. If the value is 0, the SRv6 TE policy is invalid.

The drop-upon-invalid command configured on the remote device does not affect an SRv6 TE policy generated based on a BGP IPv6 SR-TE policy route. The SRv6 TE policy is controlled by only the drop-upon-invalid command configured on the local device.

You can configure the drop-upon-invalid feature globally in SRv6 TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Globally enable the feature of dropping traffic when SRv6 TE policies become invalid.

srv6-policy drop-upon-invalid enable

By default, the drop-upon-invalid feature is disabled globally.

5. Enter SRv6 TE policy view.

policy policy-name

6. Configure the device to drop traffic when an SRv6 TE policy becomes invalid.

drop-upon-invalid { disable | enable }

By default, the drop-upon-invalid feature is not configured for an SRv6 TE policy. The configuration in SRv6 TE view applies.

Specifying the packet encapsulation type preferred in optimal route selection

About this task

As shown in Figure 14, PE 4 is the RR, and it establishes an IBGP connection with PE 1, PE 2, and PE 3, respectively. PE 1 and PE 3 support SRv6. PE 2 does not support SRv6. Both an MPLS L3VPN connection and an EVPN L3VPN over SRv6 connection exist between PE 1 and PE 3.

In this case, you can perform this task to specify the preferred encapsulation type (SRv6 encapsulation or MPLS encapsulation) for BGP optimal route selection in the L3VPN.

· If you specify the preferred keyword in the bestroute encap-type command, BGP perfers the routes with specified encapsulation type (SRv6 or MPLS) when multiple routes have the same Preferred-value attribute value. The subsequent route selection steps are the same as those in the original BGP route select procedure.

· If you do not specify the preferred keyword in the bestroute encap-type command, BGP prefers the routes with the specified encapsulation type (SRv6 or MPLS) when multiple routes have the same Preferred-value and LOCAL_PREF attribute values. The subsequent route selection steps are the same as those in the original BGP route select procedure.

For more information about BGP route selection, see BGP overview in Layer 3—IP Routing Configuration Guide.

Figure 14 MPLS L3VPN and EVPN L3VPN over SRv6 coexist

Restrictions and guidelines

If you configure both the bestroute encap-type preferred command and the bestroute nexthop-type preferred command, BGP selects the optimal route in the VPN instance by using the following procedure:

1. Drops the route with an unreachable NEXT_HOP.

2. Selects the route with the highest Preferred-value.

3. Uses the optimal route selection rule configured by the bestroute encap-type command: prefers to use an MPLS-encapsulated or SRv6-encapsulated route.

4. Uses the optimal route selection rule configured by the bestroute nexthop-type command: prefers to use a route whose next hop is an IP address or a tunnel.

5. Selects the route with the highest LOCAL_PREF.

6. Proceeds the subsequent steps in the original BGP route select procedure.

For more information about the bestroute nexthop-type command, see BGP commands in Layer 3—IP Routing Command Reference.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP-VPN instance view.

ip vpn-instance vpn-instance-name

4. Specify the packet encapsulation type preferred in optimal route selection.

bestroute encap-type { mpls | srv6 } [ preferred ]

By default, BGP does not select optimal routes according to the packet encapsulation type.

Configuring SRv6 TE policy resource usage alarm thresholds

About this task

After you configure this feature, when the number of SRv6 TE policy resources crosses the upper threshold or lower threshold, the device generates log and alarm information. The administrator can then obtain the resource usage status of SRv6 TE policies.

SRv6 TE policy resources include the following:

· Number of valid forwarding paths for all SRv6 TE policies.

· Number of entries of the SRv6Policy type in the SRv6 forwarding table.

· Number of entries of the SRv6PGROUP type in the SRv6 forwarding table.

· Number of entries of the SRv6PSIDList type in the SRv6 forwarding table.

To view SRv6 forwarding table information, use the display segment-routing ipv6 forwarding command.

Restrictions and guidelines

To view resource usage for the current SRv6 TE policy, use the display segment-routing ipv6 te policy statistics command.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Configure the alarm thresholds for resource usage of SRv6 TE policies.

srv6-policy { forwarding-path | policy | policy-group | segment-list } alarm-threshold upper-limit upper-limit-value lower-limit lower-limit-value

By default, the upper and lower alarm thresholds are 80% and 75% for all resources of SRv6 TE policies.

Enabling SRv6 TE policy logging

About this task

This feature enables the device to generate logs for SRv6 TE policy state changes and resource usage anomalies. The administrator can use the logging information to audit SRv6 TE policies. The device delivers logs to its information center. The information center processes the logs according to user-defined output rules (whether to output logs and where to output). For more information about the information center, see the network management and monitoring configuration guide for the device.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enable SRv6 TE policy logging.

srv6-policy log enable

By default, SRv6 TE policy logging is disabled.

Enabling SNMP notifications for SRv6 TE policies

About this task

This feature enables the device to send SNMP notifications about state changes and resource usage anomalies of SRv6 TE policies. For SNMP notifications to be sent correctly, you must also configure SNMP on the device. For more information about SNMP configuration, see the network management and monitoring configuration guide for the device.

Procedure

1. Enter system view.

system-view

2. Enable SNMP notifications for SRv6 TE policies.

snmp-agent trap enable srv6-policy

By default, SNMP notifications for SRv6 TE policies are disabled.

Configuring traffic forwarding statistics for SRv6 TE policies

About this task

This feature collects statistics on the traffic forwarded by SRv6 TE policies.

Restrictions and guidelines

You can configure traffic forwarding statistics for all SRv6 TE policies globally in SRv6 TE view or for a specific SRv6 TE policy in SRv6 TE policy view. The policy-specific configuration takes precedence over the global configuration. An SRv6 TE policy uses the global configuration only when it has no policy-specific configuration.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Enter SRv6 TE view.

traffic-engineering

4. Enable traffic forwarding statistics for all SRv6 TE policies.

srv6-policy forwarding statistics [ service-class ] enable

By default, traffic forwarding statistics is disabled for all SRv6 TE policies.

If you specify the service-class keyword, the device collects statistics on the total traffic as well as the traffic of each service class that are forwarded by SRv6 TE policies.

5. (Optional.) Set the traffic forwarding statistics interval for all SRv6 TE policies.

srv6-policy forwarding statistics interval interval

By default, the SRv6 TE policy forwarding statistics interval is 30 seconds.

6. Enter SRv6 TE policy view.

policy policy-name

7. Configure traffic forwarding statistics for the SRv6 TE policy.

forwarding statistics { disable | [ service-class ] enable }

By default, an SRv6 TE policy uses the traffic forwarding statistics configuration in SRv6 TE view.

If you specify the service-class keyword, the device collects statistics on the total traffic as well as the traffic of each service class that are forwarded by the SRv6 TE policy.

Display and maintenance commands for SRv6 TE policies

Execute display commands in any view. Execute reset commands in user view.

Task	Command
Display remote SRv6 SIDs protected by mirror SIDs.	display bgp [ instance instance-name ] mirror remote-sid [ end-dt4 \| end-dt46 \| end-dt6 ] [ sid ]
Display BGP peer or peer group information.	display bgp [ instance instance-name ] peer ipv6 [ sr-policy ] [ ipv6-address prefix-length \| { ipv6-address \| group-name group-name } log-info \| [ ipv6-address ] verbose ] display bgp [ instance instance-name ] peer ipv6 sr-policy [ ipv4-address mask-length \| ipv4-address log-info \| [ ipv4-address ] verbose ]
Display BGP IPv6 SR policy routing information.	display bgp [ instance instance-name ] routing-table ipv6 sr-policy [ sr-policy-prefix [ advertise-info ] ] display bgp [ instance instance-name ] routing-table ipv6 sr-policy [ as-path-acl { as-path-acl-number \| as-path-acl-name } \| as-path-regular-expression regular-expression ] display bgp [ instance instance-name ] routing-table ipv6 sr-policy [ color color-value [ end-point ipv6 ipv6-address ] \| end-point ipv6 ipv6-address ] display bgp [ instance instance-name ] routing-table ipv6 sr-policy [ peer { ipv4-address \| ipv6-address } { advertised-routes \| received-routes } [ sr-policy-prefix [ verbose ] \| color color-value [ end-point ipv6 ipv6-address ] \| end-point ipv6 ipv6-address \| statistics [ color color-value [ end-point ipv6 ipv6-address ] \| end-point ipv6 ipv6-address ] ] ] display bgp [ instance instance-name ] routing-table ipv6 sr-policy [ statistics [ color color-value [ end-point ipv6 ipv6-address ] \| end-point ipv6 ipv6-address ] ] display bgp [ instance instance-name ] routing-table ipv6 sr-policy peer { ipv4-address \| ipv6-address } { accepted-routes \| not-accepted-routes }
Display BGP peer group information.	display bgp [ instance instance-name ] group ipv6 sr-policy [ group-name group-name ]
Display BGP update group information.	display bgp [ instance instance-name ] update-group ipv6 sr-policy [ ipv4-address \| ipv6-address ]
Display remote SRv6 SIDs protected by mirror SIDs in an EVPN SRv6 network.	display evpn srv6 mirror remote-sid [ sid \| type { end-dt2u \| end-dx2 } ]
Display SRv6 TE policy information stored in the PCE	display pce segment-routing ipv6 policy database [ color color-value endpoint ipv6 ipv6-address \| policyname policy-name] [ verbose ]
display information about the SRv6 TE policy Initiate messages cached in the PCE process.	display pce segment-routing ipv6 policy initiate-cache
Display BFD information for SRv6 TE policies.	display segment-routing ipv6 te bfd [ down \| policy { { color color-value \| end-point ipv6 ipv6-address } * \| name policy-name } \| up ]
Display SRv6 TE policy database information.	display segment-routing ipv6 te database [ link \| node \| prefix \| srv6-sid ]
Display SRv6 TE forwarding information.	display segment-routing ipv6 te forwarding [ binding-sid bsid \| policy { name policy-name \| { color color-value \| end-point ipv6 ipv6-address } * } ] [ verbose ]
Display SRv6 TE traffic statistics.	display segment-routing ipv6 te forwarding [ binding-sid bsid \| policy { name policy-name \| { color color-value \| end-point ipv6 ipv6-address } * } ] traffic-statistics
Display SRv6 TE policy information.	display segment-routing ipv6 te policy [ odn \| pce ] [ name policy-name \| down \| up \| { color color-value \| end-point ipv6 ip-address } * ]
Display information about the most recent down event for SRv6 TE policies.	display segment-routing ipv6 te policy last-down-reason [ binding-sid bsid \| color color-value endpoint ipv6 ipv6-address \| policy-name policy-name ]
Display SRv6 TE policy statistics.	display segment-routing ipv6 te policy statistics
Display status information about SRv6 TE policies.	display segment-routing ipv6 te policy status [ policy-name policy-name ]
Display information about SRv6 TE policy groups.	display segment-routing ipv6 te policy-group [ group-id ] [ verbose ]
Display the reason why the specified or all SRv6 TE policy groups went down most recently.	display segment-routing ipv6 te policy-group last-down-reason [ group-id \| endpoint ipv6-address color color-value ]
Display SRv6 TE policy group statistics.	display segment-routing ipv6 te policy-group statistics
Display SBFD information for SRv6 TE policies.	display segment-routing ipv6 te sbfd [ down \| policy { { color color-value \| end-point ipv6 ipv6-address } * \| name policy-name } \| up ]
Display SRv6 TE SID list information.	display segment-routing ipv6 te segment-list [ name seglist-name \| id id-value ]
Display information about SRv6 SIDs collected from the LS database.	display segment-routing ipv6 te source-sid [ end \| end-x \| sid ]
Clear traffic forwarding statistics of SRv6 TE policies.	reset segment-routing ipv6 te forwarding statistics [ binding-sid binding-sid \| color color-value endpoint endpoint-ipv6 \| name name-value ]

‌

SRv6 TE policy configuration examples

Example: Configuring SRv6 TE policy-based forwarding

Network configuration

As shown in Figure 15, perform the following tasks on the devices to implement SRv6 TE policy-based forwarding over a specific path:

· Configure Device A through Device D to run IS-IS to implement Layer 3 connectivity.

· Configure basic SRv6 on Device A through Device D.

· Configure an SRv6 TE policy on Device A to forward user packets along path Device A > Device B > Device C > Device D.

Figure 15 Network diagram

‌

Device	Interface	IP address	Device	Interface	IP address
Device A	Loop1	1::1/128	Device B	Loop1	2::2/128
	XGE3/1/1	1000::1/64		XGE3/1/1	1000::2/64
	XGE3/1/2	4000::1/64		XGE3/1/2	2000::2/64
Device C	Loop1	3::3/128	Device D	Loop1	4::4/128
	XGE3/1/1	3000::3/64		XGE3/1/1	3000::4/64
	XGE3/1/2	2000::3/64		XGE3/1/2	4000::4/64

Procedure

1. Configure IP addresses and masks for interfaces. (Details not shown.)

2. Configure Device A:

# Configure an SRv6 SID list.

[DeviceA] segment-routing ipv6

[DeviceA-segment-routing-ipv6] encapsulation source-address 1::1

[DeviceA-segment-routing-ipv6] locator a ipv6-prefix 5000:: 64 static 32

[DeviceA-segment-routing-ipv6-locator-a] opcode 1 end no-flavor

[DeviceA-segment-routing-ipv6-locator-a] quit

[DeviceA-segment-routing-ipv6] traffic-engineering

[DeviceA-srv6-te] srv6-policy locator a

[DeviceA-srv6-te] segment-list s1

[DeviceA-srv6-te-sl-s1] index 10 ipv6 6000::1

[DeviceA-srv6-te-sl-s1] index 20 ipv6 7000::1

[DeviceA-srv6-te-sl-s1] index 30 ipv6 8000::1

[DeviceA-srv6-te-sl-s1] quit

# Create an SRv6 TE policy and set the attributes.

[DeviceA-srv6-te] policy p1

[DeviceA-srv6-te-policy-p1] binding-sid ipv6 5000::2

[DeviceA-srv6-te-policy-p1] color 10 end-point ipv6 4::4

[DeviceA-srv6-te-policy-p1] candidate-paths

[DeviceA-srv6-te-policy-p1-path] preference 10

[DeviceA-srv6-te-policy-p1-path-pref-10] explicit segment-list s1

[DeviceA-srv6-te-policy-p1-path-pref-10] quit

[DeviceA-srv6-te-policy-p1-path] quit

[DeviceA-srv6-te-policy-p1] quit

[DeviceA-srv6-te] quit

[DeviceA-segment-routing-ipv6] quit

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceA> system-view

[DeviceA] isis 1

[DeviceA-isis-1] network-entity 00.0000.0000.0001.00

[DeviceA-isis-1] cost-style wide

[DeviceA-isis-1] address-family ipv6 unicast

[DeviceA-isis-1-ipv6] segment-routing ipv6 locator a

[DeviceA-isis-1-ipv6] quit

[DeviceA-isis-1] quit

[DeviceA] interface ten-gigabitethernet 3/1/1

[DeviceA-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceA-Ten-GigabitEthernet3/1/1] quit

[DeviceA] interface ten-gigabitethernet 3/1/2

[DeviceA-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[DeviceA-Ten-GigabitEthernet3/1/2] quit

[DeviceA] interface loopback 1

[DeviceA-LoopBack1] isis ipv6 enable 1

[DeviceA-LoopBack1] quit

3. Configure Device B:

# Configure the SRv6 End.SID.

[DeviceB] segment-routing ipv6

[DeviceB-segment-routing-ipv6] locator b ipv6-prefix 6000:: 64 static 32

[DeviceB-segment-routing-ipv6-locator-b] opcode 1 end no-flavor

[DeviceB-segment-routing-ipv6-locator-b] quit

[DeviceB-segment-routing-ipv6] quit

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceB> system-view

[DeviceB] isis 1

[DeviceB-isis-1] network-entity 00.0000.0000.0002.00

[DeviceB-isis-1] cost-style wide

[DeviceB-isis-1] address-family ipv6 unicast

[DeviceB-isis-1-ipv6] segment-routing ipv6 locator b

[DeviceB-isis-1-ipv6] quit

[DeviceB-isis-1] quit

[DeviceB] interface ten-gigabitethernet 3/1/1

[DeviceB-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceB-Ten-GigabitEthernet3/1/1] quit

[DeviceB] interface ten-gigabitethernet 3/1/2

[DeviceB-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[DeviceB-Ten-GigabitEthernet3/1/2] quit

[DeviceB] interface loopback 1

[DeviceB-LoopBack1] isis ipv6 enable 1

[DeviceB-LoopBack1] quit

4. Configure Device C:

# Configure the SRv6 End.SID.

[DeviceC] segment-routing ipv6

[DeviceC-segment-routing-ipv6] locator c ipv6-prefix 7000:: 64 static 32

[DeviceC-segment-routing-ipv6-locator-c] opcode 1 end no-flavor

[DeviceC-segment-routing-ipv6-locator-c] quit

[DeviceC-segment-routing-ipv6] quit

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceC> system-view

[DeviceC] isis 1

[DeviceC-isis-1] network-entity 00.0000.0000.0003.00

[DeviceC-isis-1] cost-style wide

[DeviceC-isis-1] address-family ipv6 unicast

[DeviceC-isis-1-ipv6] segment-routing ipv6 locator c

[DeviceC-isis-1-ipv6] quit

[DeviceC-isis-1] quit

[DeviceC] interface ten-gigabitethernet 3/1/1

[DeviceC-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceC-Ten-GigabitEthernet3/1/1] quit

[DeviceC] interface ten-gigabitethernet 3/1/2

[DeviceC-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[DeviceC-Ten-GigabitEthernet3/1/2] quit

[DeviceC] interface loopback 1

[DeviceC-LoopBack1] isis ipv6 enable 1

[DeviceC-LoopBack1] quit

5. Configure Device D:

# Configure the SRv6 End.SID.

[DeviceD] segment-routing ipv6

[DeviceD-segment-routing-ipv6] locator d ipv6-prefix 8000:: 64 static 32

[DeviceD-segment-routing-ipv6-locator-d] opcode 1 end no-flavor

[DeviceD-segment-routing-ipv6-locator-d] quit

[DeviceD-segment-routing-ipv6] quit

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceD> system-view

[DeviceD] isis 1

[DeviceD-isis-1] network-entity 00.0000.0000.0004.00

[DeviceD-isis-1] cost-style wide

[DeviceD-isis-1] address-family ipv6 unicast

[DeviceD-isis-1-ipv6] segment-routing ipv6 locator d

[DeviceD-isis-1-ipv6] quit

[DeviceD-isis-1] quit

[DeviceD] interface ten-gigabitethernet 3/1/1

[DeviceD-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceD-Ten-GigabitEthernet3/1/1] quit

[DeviceD] interface ten-gigabitethernet 3/1/2

[DeviceD-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[DeviceD-Ten-GigabitEthernet3/1/2] quit

[DeviceD] interface loopback 1

[DeviceD-LoopBack1] isis ipv6 enable 1

[DeviceD-LoopBack1] quit

Verifying the configuration

# Display SRv6 TE policy information on Device A.

[DeviceA] display segment-routing ipv6 te policy

Name/ID: p1/0

Color: 10

Endpoint: 4::4

Name from BGP:

BSID:

Mode: Explicit Type: Type_2 Request state: Succeeded

Current BSID: 5000::2 Explicit BSID: 5000::2 Dynamic BSID: -

Reference counts: 4

Flags: A/BS/NC

Status: Up

AdminStatus: Up

Up time: 2020-04-02 16:08:03

Down time: 2020-04-02 16:03:48

Hot backup: Disabled

Statistics: Disabled

Statistics by service class: Disabled

Path verification: Disabled

Drop-upon-invalid: Disabled

BFD trigger path-down: Disabled

SBFD: Disabled

BFD Echo: Disabled

Forwarding index: 2150629377

Association ID: 1

Service-class: -

Rate-limit: -

PCE delegation: Disabled

PCE delegate report-only: Disabled

Reoptimization: Disabled

Encapsulation mode: -

Candidate paths state: Configured

Candidate paths statistics:

CLI paths: 1 BGP paths: 0 PCEP paths: 0 ODN paths: 0

Candidate paths:

Preference : 10

CPathName:

ProtoOrigin: CLI Discriminator: 10

Instance ID: 0 Node address: 0.0.0.0

Originator: 0, ::

Optimal: Y Flags: V/A

Dynamic: Not configured

PCEP: Not configured

Explicit SID list:

ID: 1 Name: s1

Weight: 1 Forwarding index: 2149580801

State: Up State(-): -

Verification State: -

Path MTU: 1500 Path MTU Reserved: 0

Local BSID: -

Reverse BSID: -

The output shows that the SRv6 TE policy is in up state. The device can use the SRv6 TE policy to forward packets.

# Display SRv6 TE forwarding information on Device A.

[DeviceA] display segment-routing ipv6 te forwarding verbose

Total forwarding entries: 1

Policy name/ID: p1/0

Binding SID: 5000::2

Policy forwarding index: 2150629377

Main path:

Seglist ID: 1

Seglist forwarding index: 2149580801

Weight: 1

Outgoing forwarding index: 2148532225

Interface: XGE3/1/1

Nexthop: FE80::54CB:70FF:FE86:316

Discriminator: 10

Path ID: 0

SID list: {6000::1, 7000::1, 8000::1}

# Display SRv6 forwarding information on Device A.

[DeviceA] display segment-routing ipv6 forwarding

Total SRv6 forwarding entries: 3

Flags: T - Forwarded through a tunnel

N - Forwarded through the outgoing interface to the nexthop IP address

A - Active forwarding information

B - Backup forwarding information

ID FWD-Type Flags Forwarding info

Attri-Val Attri-Val

--------------------------------------------------------------------------------

2148532225 SRv6PSIDList NA XGE3/1/1

FE80::54CB:70FF:FE86:316

{6000::1, 7000::1, 8000::1}

2149580801 SRv6PCPath TA 2148532225

2150629377 SRv6Policy TA 2149580801

Example: Configuring SRv6 TE policy egress protection

Network configuration

As shown in Figure 16, deploy an SRv6 TE policy in both directions between PE 1 and PE 2 to carry the L3VPN service. PE 2 is the egress node of the SRv6 TE policy. To improve the forwarding reliability, configure PE 3 to protect PE 2.

Figure 16 Network diagram

‌

Table 1 Interface and IP address

Device	Interface	IP Address	Device	Interface	IP Address
CE 1	XGE3/1/1	10.1.1.2/24	PE 2	Loop0	3::3/128
PE 1	Loop0	1::1/128		XGE3/1/1	10.2.1.1/24
	XGE3/1/1	10.1.1.1/24		XGE3/1/2	2002::1/64
	XGE3/1/2	2001::1/96		XGE3/1/3	2004::2/96
P	Loop0	2::2/128	PE 3	Loop0	4::4/128
	XGE3/1/1	2001::2/96		XGE3/1/1	10.3.1.1/24
	XGE3/1/2	2002::2/64		XGE3/1/2	2003::1/96
	XGE3/1/3	2003::2/96		XGE3/1/3	2004::1/96
			CE 2	XGE3/1/1	10.2.1.2/24
				XGE3/1/2	10.3.1.2/24

Prerequisites

Configure interface addresses as shown in Table 1.

Procedure

1. Configure CE 1:

# Establish an EBGP peer relationship with PE 1 and redistribute the VPN routes.

<CE1> system-view

[CE1] bgp 65410

[CE1-bgp-default] peer 10.1.1.1 as-number 100

[CE1-bgp-default] address-family ipv4 unicast

[CE1-bgp-default-ipv4] peer 10.1.1.1 enable

[CE1-bgp-default-ipv4] import-route direct

[CE1-bgp-default-ipv4] quit

[CE1-bgp-default] quit

2. Configure PE 1:

# Configure IPv6 IS-IS for backbone network connectivity.

<PE1> system-view

[PE1] isis 1

[PE1-isis-1] is-level level-1

[PE1-isis-1] cost-style wide

[PE1-isis-1] network-entity 10.1111.1111.1111.00

[PE1-isis-1] address-family ipv6 unicast

[PE1-isis-1-ipv6] quit

[PE1-isis-1] quit

[PE1] interface loopback 0

[PE1-LoopBack0] ipv6 address 1::1 128

[PE1-LoopBack0] isis ipv6 enable 1

[PE1-LoopBack0] quit

[PE1] interface ten-gigabitethernet 3/1/2

[PE1-Ten-GigabitEthernet3/1/2] ipv6 address 2001::1 96

[PE1-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[PE1-Ten-GigabitEthernet3/1/2] quit

# Configure a VPN instance and bind it to the CE-facing interface.

[PE1] ip vpn-instance vpn1

[PE1-vpn-instance-vpn1] route-distinguisher 100:1

[PE1-vpn-instance-vpn1] vpn-target 111:1

[PE1-vpn-instance-vpn1] quit

[PE1] interface ten-gigabitethernet 3/1/1

[PE1-Ten-GigabitEthernet3/1/1] ip binding vpn-instance vpn1

[PE1-Ten-GigabitEthernet3/1/1] ip address 10.1.1.1 24

[PE1-Ten-GigabitEthernet3/1/1] quit

# Establish an EBGP peer relationship with the connected CE to redistribute the VPN routes.

[PE1] bgp 100

[PE1-bgp-default] router-id 1.1.1.1

[PE1-bgp-default] ip vpn-instance vpn1

[PE1-bgp-default-vpn1] peer 10.1.1.2 as-number 65410

[PE1-bgp-default-vpn1] address-family ipv4 unicast

[PE1-bgp-default-ipv4-vpn1] peer 10.1.1.2 enable

[PE1-bgp-default-ipv4-vpn1] quit

[PE1-bgp-default-vpn1] quit

# Establish MP-IBGP peer relationships with the peer PEs.

[PE1] bgp 100

[PE1-bgp-default] peer 3::3 as-number 100

[PE1-bgp-default] peer 4::4 as-number 100

[PE1-bgp-default] peer 3::3 connect-interface loopback 0

[PE1-bgp-default] peer 4::4 connect-interface loopback 0

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 3::3 enable

[PE1-bgp-default-vpnv4] peer 4::4 enable

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] quit

# Configure L3VPN over SRv6 TE policy.

[PE1] segment-routing ipv6

[PE1-segment-routing-ipv6] encapsulation source-address 1::1

[PE1-segment-routing-ipv6] locator aaa ipv6-prefix 1:2::1:0 96 static 8

[PE1-segment-routing-ipv6-locator-aaa] opcode 1 end-dt4 vpn-instance vpn1

[PE1-segment-routing-ipv6-locator-aaa] quit

[PE1-segment-routing-ipv6] quit

[PE1] bgp 100

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 3::3 prefix-sid

[PE1-bgp-default-vpnv4] peer 4::4 prefix-sid

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] ip vpn-instance vpn1

[PE1-bgp-default-vpn1] address-family ipv4 unicast

[PE1-bgp-default-ipv4-vpn1] segment-routing ipv6 traffic-engineering best-effort

[PE1-bgp-default-ipv4-vpn1] segment-routing ipv6 locator aaa

[PE1-bgp-default-ipv4-vpn1] quit

[PE1-bgp-default-vpn1] quit

[PE1-bgp-default] quit

[PE1] isis 1

[PE1-isis-1] address-family ipv6 unicast

[PE1-isis-1-ipv6] segment-routing ipv6 locator aaa

[PE1-isis-1-ipv6] quit

[PE1-isis-1] quit

# Configure an SRv6 TE policy.

[PE1] segment-routing ipv6

[PE1-segment-routing-ipv6] traffic-engineering

[PE1-srv6-te] srv6-policy locator aaa

[PE1-srv6-te] segment-list s1

[PE1-srv6-te-s1-s1] index 10 ipv6 100:abc:1::1

[PE1-srv6-te-s1-s1] index 20 ipv6 6:5::1:2

[PE1-srv6-te-s1-s1] quit

[PE1-srv6-te] policy p1

[PE1-srv6-te-policy-p1] binding-sid ipv6 1:2::1:2

[PE1-srv6-te-policy-p1] color 10 end-point ipv6 3::3

[PE1-srv6-te-policy-p1] candidate-paths

[PE1-srv6-te-policy-p1-path] preference 10

[PE1-srv6-te-policy-p1-path-pref-10] explicit segment-list s1

[PE1-srv6-te-policy-p1-path-pref-10] quit

[PE1-srv6-te-policy-p1-path] quit

[PE1-srv6-te-policy-p1] quit

[PE1-srv6-te] quit

[PE1-segment-routing-ipv6] quit

3. Configure the P device:

# Configure IPv6 IS-IS for backbone network connectivity.

<P> system-view

[P] isis 1

[P-isis-1] is-level level-1

[P-isis-1] cost-style wide

[P-isis-1] network-entity 10.2222.2222.2222.00

[P-isis-1] address-family ipv6 unicast

[P-isis-1-ipv6] quit

[P-isis-1] quit

[P] interface loopback 0

[P-LoopBack0] ipv6 address 2::2 128

[P-LoopBack0] isis ipv6 enable 1

[P-LoopBack0] quit

[P] interface ten-gigabitethernet 3/1/1

[P-Ten-GigabitEthernet3/1/1] ipv6 address 2001::2 96

[P-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[P-Ten-GigabitEthernet3/1/1] quit

[P] interface ten-gigabitethernet 3/1/2

[P-Ten-GigabitEthernet3/1/2] ipv6 address 2002::2 96

[P-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[P-Ten-GigabitEthernet3/1/2] quit

[P] interface ten-gigabitethernet 3/1/3

[P-Ten-GigabitEthernet3/1/3] ipv6 address 2003::2 96

[P-Ten-GigabitEthernet3/1/3] isis ipv6 enable 1

[P-Ten-GigabitEthernet3/1/3] quit

# Configure SRv6.

[P] segment-routing ipv6

[P-segment-routing-ipv6] locator p ipv6-prefix 100:abc:1::0 96 static 8

[P-segment-routing-ipv6-locator-p] opcode 1 end no-flavor

[P-segment-routing-ipv6-locator-p] quit

[P-segment-routing-ipv6] quit

[P] isis 1

[P-isis-1] address-family ipv6 unicast

[P-isis-1-ipv6] segment-routing ipv6 locator p

# Configure the FRR backup nexthop information and enable egress protection.

[P-isis-1-ipv6] fast-reroute lfa level-1

[P-isis-1-ipv6] fast-reroute ti-lfa

[P-isis-1-ipv6] fast-reroute mirror enable

[P-isis-1-ipv6] quit

[P-isis-1] quit

4. Configure PE 2:

# Configure IPv6 IS-IS for backbone network connectivity.

<PE2> system-view

[PE2] isis 1

[PE2-isis-1] is-level level-1

[PE2-isis-1] cost-style wide

[PE2-isis-1] network-entity 10.3333.3333.3333.00

[PE2-isis-1] address-family ipv6 unicast

[PE2-isis-1-ipv6] quit

[PE2-isis-1] quit

[PE2] interface loopback 0

[PE2-LoopBack0] ipv6 address 3::3 128

[PE2-LoopBack0] isis ipv6 enable 1

[PE2-LoopBack0] quit

[PE2] interface ten-gigabitethernet 3/1/2

[PE2-Ten-GigabitEthernet3/1/2] ipv6 address 2002::1 96

[PE2-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[PE2-Ten-GigabitEthernet3/1/2] quit

[PE2] interface ten-gigabitethernet 3/1/3

[PE2-Ten-GigabitEthernet3/1/3] ipv6 address 2004::2 96

[PE2-Ten-GigabitEthernet3/1/3] isis ipv6 enable 1

[PE2-Ten-GigabitEthernet3/1/3] quit

# Configure a VPN instance and bind it to the CE-facing interface.

[PE2] ip vpn-instance vpn1

[PE2-vpn-instance-vpn1] route-distinguisher 100:1

[PE2-vpn-instance-vpn1] vpn-target 111:1

[PE2-vpn-instance-vpn1] quit

[PE2] interface ten-gigabitethernet 3/1/1

[PE2-Ten-GigabitEthernet3/1/1] ip binding vpn-instance vpn1

[PE2-Ten-GigabitEthernet3/1/1] ip address 10.2.1.1 24

[PE2-Ten-GigabitEthernet3/1/1] quit

# Establish an EBGP peer relationship with the connected CE to redistribute the VPN routes.

[PE2] bgp 100

[PE2-bgp-default] router-id 2.2.2.2

[PE2-bgp-default] ip vpn-instance vpn1

[PE2-bgp-default-vpn1] peer 10.2.1.2 as-number 65420

[PE2-bgp-default-vpn1] address-family ipv4 unicast

[PE2-bgp-default-ipv4-vpn1] peer 10.2.1.2 enable

[PE2-bgp-default-ipv4-vpn1] quit

[PE2-bgp-default-vpn1] quit

# Establish MP-IBGP peer relationships with the peer PEs.

[PE2] bgp 100

[PE2-bgp-default] peer 1::1 as-number 100

[PE2-bgp-default] peer 4::4 as-number 100

[PE2-bgp-default] peer 1::1 connect-interface loopback 0

[PE2-bgp-default] peer 4::4 connect-interface loopback 0

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 enable

[PE2-bgp-default-vpnv4] peer 4::4 enable

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] quit

# Configure L3VPN over SRv6 TE policy.

[PE2] segment-routing ipv6

[PE2-segment-routing-ipv6] encapsulation source-address 3::3

[PE2-segment-routing-ipv6] locator bbb ipv6-prefix 6:5::1:0 96 static 8

[PE2-segment-routing-ipv6-locator-bbb] opcode 1 end-dt4 vpn-instance vpn1

[PE2-segment-routing-ipv6-locator-bbb] opcode 2 end no-flavor

[PE2-segment-routing-ipv6-locator-bbb] quit

[PE2-segment-routing-ipv6] quit

[PE2] bgp 100

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 prefix-sid

[PE2-bgp-default-vpnv4] peer 4::4 prefix-sid

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] ip vpn-instance vpn1

[PE2-bgp-default-vpn1] address-family ipv4 unicast

[PE2-bgp-default-ipv4-vpn1] segment-routing ipv6 traffic-engineering best-effort

[PE2-bgp-default-ipv4-vpn1] segment-routing ipv6 locator bbb

[PE2-bgp-default-ipv4-vpn1] quit

[PE2-bgp-default-vpn1] quit

[PE2-bgp-default] quit

[PE2] isis 1

[PE2-isis-1] address-family ipv6 unicast

[PE2-isis-1-ipv6] segment-routing ipv6 locator bbb

[PE2-isis-1-ipv6] quit

[PE2-isis-1] quit

5. Configure PE 3:

# Configure IPv6 IS-IS for backbone network connectivity.

<PE3> system-view

[PE3] isis 1

[PE3-isis-1] is-level level-1

[PE3-isis-1] cost-style wide

[PE3-isis-1] network-entity 10.4444.4444.4444.00

[PE3-isis-1] address-family ipv6 unicast

[PE3-isis-1-ipv6] quit

[PE3-isis-1] quit

[PE3] interface loopback 0

[PE3-LoopBack0] ipv6 address 4::4 128

[PE3-LoopBack0] isis ipv6 enable 1

[PE3-LoopBack0] quit

[PE3] interface ten-gigabitethernet 3/1/2

[PE3-Ten-GigabitEthernet3/1/2] ipv6 address 2003::1 96

[PE3-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[PE3-Ten-GigabitEthernet3/1/2] quit

[PE3] interface ten-gigabitethernet 3/1/3

[PE3-Ten-GigabitEthernet3/1/3] ipv6 address 2004::1 96

[PE3-Ten-GigabitEthernet3/1/3] isis ipv6 enable 1

[PE3-Ten-GigabitEthernet3/1/3] quit

# Configure a VPN instance and bind it to the CE-facing interface.

[PE3] ip vpn-instance vpn1

[PE3-vpn-instance-vpn1] route-distinguisher 100:1

[PE3-vpn-instance-vpn1] vpn-target 111:1

[PE3-vpn-instance-vpn1] quit

[PE3] interface ten-gigabitethernet 3/1/1

[PE3-Ten-GigabitEthernet3/1/1] ip binding vpn-instance vpn1

[PE3-Ten-GigabitEthernet3/1/1] ip address 10.3.1.1 24

[PE3-Ten-GigabitEthernet3/1/1] quit

# Establish an EBGP peer relationship with the connected CE to redistribute the VPN routes.

[PE3] bgp 100

[PE3-bgp-default] router-id 3.3.3.3

[PE3-bgp-default] ip vpn-instance vpn1

[PE3-bgp-default-vpn1] peer 10.3.1.2 as-number 65420

[PE3-bgp-default-vpn1] address-family ipv4 unicast

[PE3-bgp-default-ipv4-vpn1] peer 10.3.1.2 enable

[PE3-bgp-default-ipv4-vpn1] quit

[PE3-bgp-default-vpn1] quit

# Establish MP-IBGP peer relationships with the peer PEs.

[PE3] bgp 100

[PE3-bgp-default] peer 1::1 as-number 100

[PE3-bgp-default] peer 3::3 as-number 100

[PE3-bgp-default] peer 1::1 connect-interface loopback 0

[PE3-bgp-default] peer 3::3 connect-interface loopback 0

[PE3-bgp-default] address-family vpnv4

[PE3-bgp-default-vpnv4] peer 1::1 enable

[PE3-bgp-default-vpnv4] peer 3::3 enable

[PE3-bgp-default-vpnv4] quit

[PE3-bgp-default] quit

# Configure the source address in the outer IPv6 header of SRv6 VPN packets.

[PE3] segment-routing ipv6

[PE3-segment-routing-ipv6] encapsulation source-address 4::4

# Configure an End.M SID to protect PE 2.

[PE3-segment-routing-ipv6] locator ccc ipv6-prefix 9:7::1:0 96 static 8

[PE3-segment-routing-ipv6-locator-ccc] opcode 1 end-m mirror-locator 6:5::1:0 96

[PE3-segment-routing-ipv6-locator-ccc] quit

[PE3-segment-routing-ipv6] quit

# Recurse the VPN routes to the End.M SID route.

[PE3] bgp 100

[PE3-bgp-default] address-family vpnv4

[PE3-bgp-default-vpnv4] peer 1::1 prefix-sid

[PE3-bgp-default-vpnv4] peer 3::3 prefix-sid

[PE3-bgp-default-vpnv4] quit

[PE3-bgp-default] ip vpn-instance vpn1

[PE3-bgp-default-vpn1] address-family ipv4 unicast

[PE3-bgp-default-ipv4-vpn1] segment-routing ipv6 locator ccc

[PE3-bgp-default-ipv4-vpn1] quit

[PE3-bgp-default-vpn1] quit

[PE3-bgp-default] quit

[PE3] isis 1

[PE3-isis-1] address-family ipv6 unicast

[PE3-isis-1-ipv6] segment-routing ipv6 locator ccc

[PE3-isis-1-ipv6] quit

[PE3-isis-1] quit

6. Configure CE 2:

# Establish an EBGP peer relationship with PEs and redistribute the VPN routes.

<CE2> system-view

[CE2] bgp 65420

[CE2-bgp-default] peer 10.2.1.1 as-number 100

[CE2-bgp-default] peer 10.3.1.1 as-number 100

[CE2-bgp-default] address-family ipv4 unicast

[CE2-bgp-default-ipv4] peer 10.2.1.1 enable

[CE2-bgp-default-ipv4] peer 10.3.1.1 enable

[CE2-bgp-default-ipv4] import-route direct

[CE2-bgp-default-ipv4] quit

[CE2-bgp-default] quit

Verifying the configuration

# Display the SRv6 TE policy configuration. The output shows that the SRv6 TE policy is up for traffic forwarding.

[PE1] display segment-routing ipv6 te policy

Name/ID: p1/0

Color: 10

End-point: 3::3

Name from BGP:

BSID:

Mode: Explicit Type: Type_2 Request state: Succeeded

Current BSID: 1:2::1:2 Explicit BSID: 1:2::1:2 Dynamic BSID: -

Reference counts: 4

Flags: A/BS/NC

Status: Up

AdminStatus: Up

Up time: 2020-10-28 09:10:33

Down time: 2020-10-28 09:09:32

Hot backup: Disabled

Statistics: Disabled

Statistics by service class: Disabled

Path verification: Disabled

Drop-upon-invalid: Disabled

BFD trigger path-down: Disabled

SBFD: Disabled

BFD Echo: Disabled

Forwarding index: 2150629377

Association ID: 1

Service-class: -

Rate-limit: -

PCE delegation: Disabled

PCE delegate report-only: Disabled

Reoptimization: Disabled

Encapsulation mode: -

Candidate paths state: Configured

Candidate paths statistics:

CLI paths: 1 BGP paths: 0 PCEP paths: 0 ODN paths: 0

Candidate paths:

Preference : 10

CPathName:

ProtoOrigin: CLI Discriminator: 10

Instance ID: 0 Node address: 0.0.0.0

Originator: 0, ::

Optimal: Y Flags: V/A

Dynamic: Not configured

PCEP: Not configured

Explicit SID list:

ID: 1 Name: s1

Weight: 1 Forwarding index: 2149580801

State: Up State(-): -

Verification State: -

Path MTU: 1500 Path MTU Reserved: 0

Local BSID: -

Reverse BSID: -

# Display SRv6 TE policy forwarding information on PE 1.

[PE1] display segment-routing ipv6 te forwarding verbose

Total forwarding entries: 1

Policy name/ID: p1/0

Binding SID: 1:2::1:2

Forwarding index: 2150629377

Main path:

Seglist ID: 1

Seglist forwarding index: 2149580801

Weight: 1

Outgoing forwarding index: 2148532225

Interface: XGE3/1/2

Nexthop: FE80::988A:B5FF:FED9:316

Discriminator: 10

Path ID: 0

SID list: {100:ABC:1::1, 6:5::1:2}

# Display SRv6 TE policy forwarding path information on PE 1.

[PE1] display segment-routing ipv6 forwarding

Total SRv6 forwarding entries: 3

Flags: T - Forwarded through a tunnel

N - Forwarded through the outgoing interface to the nexthop IP address

A - Active forwarding information

B - Backup forwarding information

ID FWD-Type Flags Forwarding info

Attri-Val Attri-Val

--------------------------------------------------------------------------------

2148532225 SRv6PSIDList NA XGE3/1/2

FE80::988A:B5FF:FED9:316

{100:ABC:1::1, 6:5::1:2}

2149580801 SRv6PCPath TA 2148532225

2150629377 SRv6Policy TA 2149580801

# Display remote SRv6 SIDs protected by End.M SIDs on PE 3.

[PE3] display bgp mirror remote-sid

Remote SID: 6:5::1:1

Remote SID type: End.DT4

Mirror locator: 6:5::1:0/96

Vpn instance name: vpn1

# Display the End.M SID carried in the IS-IS IPv6 route on the P device.

[P] display isis route ipv6 6:5::1:0 96 verbose

Route information for IS-IS(1)

------------------------------

Level-1 IPv6 forwarding table

-----------------------------

IPv6 dest : 6:5::1:0/96

Flag : R/-/- Cost : 10

Admin tag : - Src count : 3

Nexthop : FE80::988A:BDFF:FEB6:417

NexthopFlag: -

Interface : XGE3/1/2

Mirror FRR:

Interface : XGE3/1/3

BkNextHop : FE80::988A:C6FF:FE0D:517

LsIndex : 0x80000001

Backup label stack(top->bottom): {9:7::1:1}

Nib ID : 0x24000006

Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set

Typically, VPN traffic from CE 1 to CE 2 is forwarded over the CE 1-PE 1-P-PE 2-CE 2 path. When PE 2 fails, the P device switches traffic to the mirror FRR path for the SRv6 TE policy when it detects that the next hop (PE 2) is unreachable.

# Shut down the interface that connects P to PE 2.

[P] interface ten-gigabitethernet 3/1/2

[P-Ten-GigabitEthernet3/1/2] shut

[P-Ten-GigabitEthernet3/1/2] quit

# Display the IS-IS IPv6 route information. The output shows that the nexthop interface becomes the backup interface.

[P] display isis route ipv6 6:5::1:0 96 verbose

Route information for IS-IS(1)

------------------------------

Level-1 IPv6 forwarding table

-----------------------------

IPv6 dest : 6:5::1:0/96

Flag : R/-/- Cost : 20

Admin tag : - Src count : 3

Nexthop : FE80::988A:BDFF:FEB6:417

NexthopFlag: -

Interface : XGE3/1/2

Mirror FRR:

Interface : XGE3/1/3

BkNextHop : FE80::988A:C6FF:FE0D:517

LsIndex : 0x80000001

Backup label stack(top->bottom): {9:7::1:1}

Nib ID : 0x24000006

Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set

# Display SRv6 TE policy information on PE 1. The output shows that the SRv6 TE policy is still up.

[PE1] display segment-routing ipv6 te policy

Name/ID: p1/0

Color: 10

End-point: 3::3

Name from BGP:

BSID:

Mode: Explicit Type: Type_2 Request state: Succeeded

Current BSID: 1:2::1:2 Explicit BSID: 1:2::1:2 Dynamic BSID: -

Reference counts: 4

Flags: A/BS/NC

Status: Up

AdminStatus: Up

Up time: 2020-10-28 09:10:33

Down time: 2020-10-28 09:09:32

Hot backup: Disabled

Statistics: Disabled

Statistics by service class: Disabled

Path verification: Disabled

Drop-upon-invalid: Disabled

BFD trigger path-down: Disabled

SBFD: Disabled

BFD Echo: Disabled

Forwarding index: 2150629377

Association ID: 1

Service-class: -

Rate-limit: -

PCE delegation: Disabled

PCE delegate report-only: Disabled

Reoptimization: Disabled

Encapsulation mode: -

Candidate paths state: Configured

Candidate paths statistics:

CLI paths: 1 BGP paths: 0 PCEP paths: 0 ODN paths: 0

Candidate paths:

Preference : 10

CPathName:

ProtoOrigin: CLI Discriminator: 10

Instance ID: 0 Node address: 0.0.0.0

Originator: 0, ::

Optimal: Y Flags: V/A

Dynamic: Not configured

PCEP: Not configured

Explicit SID list:

ID: 1 Name: s1

Weight: 1 Forwarding index: 2149580801

State: Up State(-): -

Verification State: -

Path MTU: 1500 Path MTU Reserved: 0

Local BSID: -

Reverse BSID: -

Example: Configuring SRv6 TE policy through ODN

Network configuration

As shown in Figure 17, configuring automatic creation of SRv6 TE policies between Device B and Device E by using ODN to forward the traffic between Device A and Device F.

Figure 17 Network diagram

‌

Table 2 Interface and IP address assignment

Device	Interface	IP Address	Device	Interface	IP Address
Device A	XGE3/1/1	1000::1/64	Device F	XGE3/1/1	6000::2/64
Device B	Loop0	1::1/128	Device E	Loop0	3::3/128
	XGE3/1/1	1000::2/64		XGE3/1/1	6000::1/64
	XGE3/1/2	2000::1/64		XGE3/1/2	4000::/64
	XGE3/1/3	3000::1/64		XGE3/1/3	5000::1/64
Device C	XGE3/1/1	4000::2/64	Device D	XGE3/1/1	5000::2/64
	XGE3/1/2	2002::2/64		XGE3/1/2	3000::2/64

Prerequisites

Configure interface addresses as shown in Table 2.

Proedure

1. Configure Device A:

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceA> system-view

[DeviceA] isis 1

[DeviceA-isis-1] cost-style wide

[DeviceA-isis-1] network-entity 00.0000.0000.0001.00

[DeviceA-isis-1] address-family ipv6 unicast

[DeviceA-isis-1-ipv6] quit

[DeviceA-isis-1] quit

[DeviceA] interface ten-gigabitethernet 3/1/1

[DeviceA-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceA-Ten-GigabitEthernet3/1/1] quit

2. Configure Device B:

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceB> system-view

[DeviceB] isis 1

[DeviceB-isis-1] cost-style wide

[DeviceB-isis-1] network-entity 00.0000.0000.0002.00

[DeviceB-isis-1] address-family ipv6 unicast

[DeviceB-isis-1-ipv6] quit

[DeviceB-isis-1] quit

[DeviceB] interface ten-gigabitethernet 3/1/1

[DeviceB-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceB-Ten-GigabitEthernet3/1/1] quit

[DeviceB] interface ten-gigabitethernet 3/1/2

[DeviceB-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[DeviceB-Ten-GigabitEthernet3/1/2] quit

[DeviceB] interface ten-gigabitethernet 3/1/3

[DeviceB-Ten-GigabitEthernet3/1/3] isis ipv6 enable 1

[DeviceB-Ten-GigabitEthernet3/1/3] quit

[DeviceB] interface loopback 0

[DeviceB-LoopBack0] isis ipv6 enable 1

[DeviceB-LoopBack0] quit

# Establish a BGP peer relationship with Device E.

[DeviceB] bgp 100

[DeviceB-bgp-default] router-id 1.1.1.1

[DeviceB-bgp-default] peer 3::3 as-number 100

[DeviceB-bgp-default] peer 3::3 connect-interface loopback 0

[DeviceB-bgp-default] address-family ipv6

[DeviceB-bgp-default-ipv6] peer 3::3 enable

[DeviceB-bgp-default-ipv6] quit

[DeviceB-bgp-default] address-family ipv6 sr-policy

[DeviceB-bgp-default-srpolicy-ipv6] peer 3::3 enable

[DeviceB-bgp-default-srpolicy-ipv6] quit

[DeviceB-bgp-default] quit

# Configure an SRv6 locator.

[DeviceB] segment-routing ipv6

[DeviceB-segment-routing-ipv6] encapsulation source-address 1::1

[DeviceB-segment-routing-ipv6] locator b ipv6-prefix 20:1:: 96 static 24

[DeviceB-segment-routing-ipv6-locator-b] opcode 1 end no-flavor

[DeviceB-segment-routing-ipv6-locator-b] quit

[DeviceB-segment-routing-ipv6] quit

# Configure ODN to create an SRv6 TE policy automatically.

[DeviceB] segment-routing ipv6

[DeviceB-segment-routing-ipv6] traffic-engineering

[DeviceB-srv6-te] srv6-policy locator b

[DeviceB-srv6-te] on-demand color 1

# Enable path computation using PCE.

[DeviceB-srv6-te-odn-1] dynamic

[DeviceB-srv6-te-odn-1-dynamic] pcep

[DeviceB-srv6-te-odn-1] quit

[DeviceB-srv6-te] quit

[DeviceB-segment-routing-ipv6] quit

[DeviceB] isis 1

[DeviceB-isis-1] address-family ipv6 unicast

[DeviceB-isis-1-ipv6] segment-routing ipv6 locator b

[DeviceB-isis-1-ipv6] quit

[DeviceB-isis-1] quit

3. Configure Device C:

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceC> system-view

[DeviceC] isis 1

[DeviceC-isis-1] cost-style wide

[DeviceC-isis-1] network-entity 00.0000.0000.0003.00

[DeviceC-isis-1] address-family ipv6 unicast

[DeviceC-isis-1-ipv6] quit

[DeviceC-isis-1] quit

[DeviceC] interface ten-gigabitethernet 3/1/1

[DeviceC-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceC-Ten-GigabitEthernet3/1/1] quit

[DeviceC] interface ten-gigabitethernet 3/1/2

[DeviceC-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[DeviceC-Ten-GigabitEthernet3/1/2] quit

[DeviceC] interface loopback 0

[DeviceC-LoopBack1] isis ipv6 enable 1

[DeviceC-LoopBack1] quit

4. Configure Device D:

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceD> system-view

[DeviceD] isis 1

[DeviceD-isis-1] cost-style wide

[DeviceD-isis-1] network-entity 00.0000.0000.0004.00

[DeviceD-isis-1] address-family ipv6 unicast

[DeviceD-isis-1-ipv6] quit

[DeviceD-isis-1] quit

[DeviceD] interface ten-gigabitethernet 3/1/1

[DeviceD-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceD-Ten-GigabitEthernet3/1/1] quit

[DeviceD] interface ten-gigabitethernet 3/1/2

[DeviceD-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[DeviceD-Ten-GigabitEthernet3/1/2] quit

[DeviceD] interface loopback 0

[DeviceD-LoopBack0] isis ipv6 enable 1

[DeviceD-LoopBack0] quit

5. Configure Device E:

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceE> system-view

[DeviceE] isis 1

[DeviceE-isis-1] cost-style wide

[DeviceE-isis-1] network-entity 00.0000.0000.0005.00

[DeviceE-isis-1] address-family ipv6 unicast

[DeviceE-isis-1-ipv6] quit

[DeviceE-isis-1] quit

[DeviceE] interface ten-gigabitethernet 3/1/1

[DeviceE-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceE-Ten-GigabitEthernet3/1/1] quit

[DeviceE] interface ten-gigabitethernet 3/1/2

[DeviceE-Ten-GigabitEthernet3/1/2] isis ipv6 enable 1

[DeviceE-Ten-GigabitEthernet3/1/2] quit

[DeviceE] interface ten-gigabitethernet 3/1/3

[DeviceE-Ten-GigabitEthernet3/1/3] isis ipv6 enable 1

[DeviceE-Ten-GigabitEthernet3/1/3] quit

[DeviceE] interface loopback 0

[DeviceE-LoopBack0] isis ipv6 enable 1

[DeviceE-LoopBack0] quit

[DeviceE] interface loopback 1

[DeviceE-LoopBack1] ipv6 address 2::2 128

[DeviceE-LoopBack1] quit

# Establish a BGP peer relationship with Device B.

[DeviceE] bgp 100

[DeviceE-bgp-default] router-id 3.3.3.3

[DeviceE-bgp-default] peer 1::1 as-number 100

[DeviceE-bgp-default] peer 1::1 connect-interface loopback 0

[DeviceE-bgp-default] address-family ipv6

[DeviceE-bgp-default-ipv6] peer 1::1 enable

[DeviceE-bgp-default-ipv6] network 2::2 128

[DeviceE-bgp-default-ipv6] quit

[DeviceE-bgp-default] address-family ipv6 sr-policy

[DeviceE-bgp-default-srpolicy-ipv6] peer 1::1 enable

[DeviceE-bgp-default-srpolicy-ipv6] quit

[DeviceE-bgp-default] quit

# Configure a route policy to add a color attribute to the export routes.

[DeviceE] route-policy 1 permit node 10

[DeviceE-route-policy-1-10] apply extcommunity color 01:1

[DeviceE-route-policy-1-10] quit

[DeviceE] bgp 100

[DeviceE-bgp-default] address-family ipv6 unicast

[DeviceE-bgp-default-ipv6] peer 1::1 route-policy 1 export

[DeviceE-bgp-default-ipv6] peer 1::1 advertise-community

[DeviceE-bgp-default-ipv6] peer 1::1 advertise-ext-community

[DeviceE-bgp-default-ipv6] quit

[DeviceE-bgp-default] quit

6. Configure Device F:

# Configure IS-IS and set the IS-IS cost style to wide.

<DeviceF> system-view

[DeviceF] isis 1

[DeviceF-isis-1] network-entity 00.0000.0000.0006.00

[DeviceF-isis-1] cost-style wide

[DeviceF-isis-1] address-family ipv6 unicast

[DeviceF-isis-1-ipv6] quit

[DeviceF-isis-1] quit

[DeviceF] interface ten-gigabitethernet 3/1/1

[DeviceF-Ten-GigabitEthernet3/1/1] isis ipv6 enable 1

[DeviceF-Ten-GigabitEthernet3/1/1] quit

Verifying the configuration

# Display information about the ODN-created SRv6 TE policy on Device B.

[DeviceB] display segment-routing ipv6 te policy

Name/ID: sr-1-3::3/0

Color: 1

End-point: 3::3

Name from BGP: sr-1-3::3

Name from PCE:

BSID:

Mode: Dynamic Type: Type_2 Request state: Succeeded

Current BSID: 20:1::100:0 Explicit BSID: - Dynamic BSID: 20:1::100:0

Reference counts: 4

Flags: A/BS/NC

Status: Up

AdminStatus: Up

Up time: 2020-12-01 15:58:12

Down time: 2020-12-01 15:58:12

Hot backup: Disabled

Statistics: Disabled

Statistics by service class: Disabled

Path verification: Disabled

Drop-upon-invalid: Disabled

BFD trigger path-down: Disabled

SBFD: Disabled

BFD Echo: Disabled

Forwarding index: 2150629377

Association ID: 1

Service-class: -

Rate-limit: -

PCE delegation: Disabled

PCE delegate report-only: Disabled

Reoptimization: Disabled

Encapsulation mode: -

Candidate paths state: Not configured

Candidate paths statistics:

CLI paths: 0 BGP paths: 0 PCEP paths: 0 ODN paths: 2

Candidate paths:

Preference : 100

CPathName: sr-1-3::3

ProtoOrigin: BGP Discriminator: 100

Instance ID: 0 Node address: 0.0.0.0

Originator: 0, ::

Optimal: N Flags: None

Dynamic: Configured

PCEP: Configured

Candidate paths:

Preference : 200

CPathName: sr-1-3::3

ProtoOrigin: BGP Discriminator: 200

Instance ID: 0 Node address: 0.0.0.0

Originator: 0, ::

Optimal: N Flags: BN

Dynamic: Not configured

PCEP: Not configured

# Display the forwarding path information of the SRv6 TE policy.

[DeviceB] display segment-routing ipv6 forwarding

Total SRv6 forwarding entries: 1

Flags: T - Forwarded through a tunnel

N - Forwarded through the outgoing interface to the nexthop IP address

A - Active forwarding information

B - Backup forwarding information

ID FWD-Type Flags Forwarding info

--------------------------------------------------------------------------------

2150630377 SRv6Policy TA 2149581800

# Display the forwarding information of the SRv6 TE policy.

[DeviceB] display segment-routing ipv6 te forwarding verbose

Total forwarding entries: 1

Policy name/ID: sr-1-3::3/1001

Binding SID: 20:1::100:0

Forwarding index: 2150630377

Main path:

Seglist ID: 4369

Seglist forwarding index: 2149581800

Weight: 1

Outgoing forwarding index: 2148533223

Interface: GE1/0/3

Nexthop: FE80::7AAA:12FF:FED8:309

Discriminator: 100

Path ID: 0

SID list: {6:5::1:5}

# Display BGP route information for the SRv6 TE policy.

[DeviceB] display bgp routing-table ipv6 3::3 128

BGP local router ID: 1.1.1.1

Local AS number: 100

Paths: 1 available, 1 best

BGP routing table information of 3::3/128:

From : 3::3 (2.2.2.2)

Rely nexthop : FE80::7AAA:12FF:FED8:309

Original nexthop: 3::3

Out interface : GigabitEthernet1/0/3

Route age : 00h17m00s

OutLabel : NULL

Ext-Community : <CO-Flag:Color(01:1)>

RxPathID : 0x0

TxPathID : 0xffffffff

AS-path : (null)

Origin : incomplete

Attribute value : MED 0, localpref 100, pref-val 0

State : valid, internal, not preferred for igp-cost, not ECMP for igp-cost

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : gw

Rely tunnel IDs : 2150630377

11-Segment Routing Configuration Guide

Configuring SRv6 TE policies

About SRv6 TE policies

Dynamic path calculation based on affinity attribute

Dynamic path calculation based on Flex-Algo

Basic concepts

PCE path computation

Traffic steering to an SRv6 TE policy

SRv6 TE policy path selection

About SRv6 TE policy CBTS

How SRv6 TE policy CBTS works

SRv6 TE policy selection rules

SRv6 TE policy CBTS application scenario

BFD for SRv6 TE policy

Echo BFD for SRv6 TE policy

Protection path failure

Transit node protection

Special processing on the source node

End.M SID

Remote SRv6 SID

Route advertisement

Packet forwarding

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

Discovering PCEs

About this task

Procedure

Abou this task

Procedure

About this task

Procedure

Configuring a candidate path to use manually configured SID lists

About this task

Restrictions and guidelines

Procedure

Creating a name-to-bit mapping for an affinity attribute

Configuring affinity attribute rules

Configuring dynamic path calculation based on affinity attribute rule

Prerequisites

Procedure

Creating a name-to-bit mapping for an affinity attribute

Configuring affinity attribute rules

Configuring dynamic path calculation based on affinity attribute rule

Prerequisites

Procedure

About this task

Restrictions and guidelines

Prerequisites

Configuring PCE delegation parameters

Enabling delegation

About this task

Prerequisites

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Prerequisites

Procedure

Shutting down an SRv6 TE policy

About this task

Procedure

Configuring BGP to redistribute BGP IPv6 SR policy routes

About this task

Procedure

About this task

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Procedure

Maintaining BGP sessions

Prerequisites

Procedure

About this task