IP L3VPN over SRv6 uses SRv6 tunnels to carry IP L3VPN services. This technology establishes SRv6 tunnels among geographically dispersed customer sites over an IPv6 network and transparently forwards Layer 3 customer traffic to remote sites over the IPv6 network through the tunnels. For more information about MPLS L3VPN configuration, see MPLS Configuration Guide.

Basic principle

Figure 1 shows a typical IP L3VPN over SRv6 network.

· PE 1 and PE 2 use BGP to advertise IPv4 or IPv6 VPN routes to each other over the IPv6 backbone network. The VPN routes contain private network routing information and SID information.

· The PEs have a single-hop SRv6 tunnel between them and they use the SRv6 tunnel to forward VPN traffic across sites.

· The devices in the IPv6 backbone network forward the SRv6-encapsulated VPN traffic through the optimal path calculated by IGP.

IP L3VPN over SRv6 connects geographically dispersed sites that belong to the same VPN over the IPv6 backbone network.

If the customer sites belong to the public network, IP L3VPN over SRv6 takes the public network as a special VPN. The PEs establish a single-hop SRv6 tunnel between them and use the SRv6 tunnel to forward public network traffic across sites. This scenario is also called the public network over SRv6 scenario.

Figure 1 Network diagram

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Route advertisement

The route advertisement process of IPv4 L3VPN over SRv6 is similar to that of IPv6 L3VPN over SRv6. This section uses IPv4 L3VPN over SRv6 to illustrate the process.

As shown in Figure 1, local routes of CE 1 are advertised to CE 2 by using the following process:

1. CE 1 uses static routing, OSPF, IS-IS, EBGP, or IBGP to advertise routes of the local site to PE 1.

2. After learning the route information of CE 1, PE 1 stores the private routes to the routing table of the VPN instance. In this example, VPN instance 1 is used. Then, PE 1 converts the routes to BGP VPNv4 routes and advertises the BGP VPNv4 routes to PE 2 by using MP-BGP. The BGP VPNv4 routes carry the RD, RT, and SID attributes (the SID attribute is used as the private network label).

¡ If next hop-based dynamic SID allocation is not used, all private network routes of the VPN instance are allocated the same End.DT4 or End.DT46 SID.

¡ If next hop-based dynamic SID allocation is used, private network routes with the same next hop are allocated the same End.DX4 SID in the VPN instance.

3. When PE 2 receives the routes advertised by PE 1, it adds the routes to the routing table of VPN 1, converts the routes to IPv4 routes, and advertises the IPv4 routes to CE 2.

4. By adding the received IPv4 routes to the routing table, CE 2 learns the private network routes of CE 1.

Packet forwarding

IP L3VPN over SRv6 supports the following route recursion modes:

· SRv6 BE mode.

· SRv6 TE mode.

· SRv6 TE and SRv6 BE hybrid mode.

The packet forwarding process differs by the route recursion mode in use.

SRv6 BE mode

This mode is also called SID-based forwarding mode. In this mode, a PE forwards an SRv6 packet by searching the IPv6 routing table based on the SRv6 SID encapsulated in the packet.

The packet forwarding process is similar for IPv4 L3VPN over SRv6 and IPv6 L3VPN over SRv6. This section uses IPv4 L3VPN over SRv6 and VPN sites to illustrate the process.

As shown in Figure 1, CE 2 forwards an IPv4 packet to CE 1 as follows:

1. CE 2 sends the IPv4 packet to PE 2.

2. PE 2 receives the packet on an interface associated with the VPN instance (in this example, the VPN instance is VPN 1). PE 2 searches for a route that matches the destination IPv4 address of the packet in the routing table of the VPN instance. The corresponding End.DT4, End.DT46, or End.DX4 SID is found. Then, PE 2 encapsulates an outer IPv6 header for the packet. The End.DT4, End.DT46, or End.DX4 SID is encapsulated in the outer IPv6 header as the destination address.

3. PE 2 searches the IPv6 routing table based on the End.DT4, End.DT46, or End.DX4 SID for the optimal IGP route and forwards the packet to P through the route.

4. P searches the IPv6 routing table based on the End.DT4, End.DT46, or End.DX4 SID for the optimal IGP route and forwards the packet to PE 1 through the route.

5. When PE 1 receives the packet, it processes the packet as follows:

¡ If the packet header contains an End.DT4 or End.DT46 SID, PE 1 searches the local SID forwarding table for the SID and removes the outer IPv6 header. Then, PE 1 matches the packet to VPN 1 based on the SID, searches the routing table of VPN 1 for the optimal route, and forwards the packet to CE 1.

¡ If the packet header contains an End.DX4 SID, PE 1 searches the local SID forwarding table for the SID and removes the outer IPv6 header. Then, PE 1 forwards the packet to CE 1 according to the next hop and output interface bound to the SID.

SRv6 TE mode

This mode is also called SRv6 TE policy-based forwarding mode. In this mode, when a PE forwards a customer packet, it first searches for a matching SRv6 TE policy based on the packet attributes. Then, the PE adds an SRH to the packet. The SRH includes the destination SRv6 SID and the SID list of the SRv6 TE policy. Finally, the PE forwards the encapsulated packet based on the SRv6 TE policy.

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

· Color—The device searches for an SRv6 TE policy that has the same color and endpoint address as the color and nexthop address of a VPN route. If a matching SRv6 TE policy exists, the device recurses the VPN route to that SRv6 TE policy. When the device receives packets that match the VPN route, it forwards the packets through the SRv6 TE policy.

· Tunnel policy—The device searches the tunnel policies for a matching SRv6 TE policy based on the next hop of a matching route. Configure a preferred tunnel or load sharing tunnel policy that uses the SRv6 TE policy. In this way, the SRv6 TE policy will be used as the public tunnel to carry the SRv6 PW that forwards the packets of private network packets.

For more information about tunnel policies, see MPLS Configuration Guide. For more information about SRv6 TE policies, see "Configuring SRv6 TE policies."

SRv6 TE and SRv6 BE hybrid mode

In this mode, the PE preferentially uses the SRv6 TE mode to forward a packet. If no SRv6 TE policy is available for the packet, the PE forwards the packet in SRv6 BE mode.

Intercommunication between SRv6 and MPLS networks

If the private network routes at one site must pass through both SRv6 and MPLS networks to reach another site, ensure that the SRv6 and MPLS networks can communicate with each other. For this purpose, use the following solutions:

· HoVPN.

HoVPN

Hierarchy of VPN (HoVPN), also called Hierarchy of PE (HoPE), prevents PEs from being bottlenecks and is applicable to large-scale VPN deployment.

HoVPN divides PEs into underlayer PEs (UPEs) or user-end PEs, middle-level PEs (MPEs), and superstratum PEs (SPEs) or service provider-end PEs. UPEs, MPEs, and SPEs have different functions and comprise a hierarchical PE. The HoPE and common PEs can coexist in a network.

UPEs, MPEs, and SPEs play the following different roles:

· A UPE is directly connected to CEs. It provides user access.

· An MPE is connected to UPEs and SPEs. It manages route information advertised by UPEs.

· An SPE resides inside the service provider network. It manages and advertises VPN routes.

As shown in Figure 2, in an HoVPN network, the UPE, MPE, and SPE are connected through MPLS and SRv6 networks. L3VPN data is transmitted over the backbone network in the following scenarios:

· L3VPN over MPLS-to-SRv6.

· L3VPN over SRv6-to-MPLS.

Figure 2 Basic architecture of HoVPN

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As shown in Figure 2, the MPE connects the MPLS network and SRv6 network. Configure the MPE to reoriginate routes and advertise the optimal routes.

· When the MPE receives VPNv4 or VPNv6 routes from the MPLS L3VPN network, it compares the export targets of the routes with the local import targets of the VPN instance. If they match, the MPE modifies the RD and route target attributes in the routes, assigns them SRv6 SIDs, and associate the SRv6 SID and private label of each route. Then, the MPE advertises the reoriginated routes to the SRv6 network. The supported SRv6 SIDs include End.DT4, End.DT6, End.DT46, End.DX4, and End.DX6 SIDs.

· When the MPE receives VPNv4 or VPNv6 routes from the SRv6 network, it compares the export targets of the routes with the local import targets of the VPN instance. If they match, the MPE modifies the RD and route target attributes in the routes, assign them private labels, and associate the private label and SRv6 SID of each route. Then, the MPE advertises the reoriginated routes to the MPLS L3VPN network.

When the UPE and SPE learn the reoriginated optimal routes, they forward traffic according to the route information. For example, in the L3VPN over MPLS-to-SRv6 scenario, packets are forwarded as follows:

1. When the UPE receives a packet from CE 1, it encapsulates MPLS labels to the packet and forwards the packet to the MPE.

2. When the MPE receives the packet, it removes the private label from the packet and encapsulates an SRv6 SID to the packet according to the private label-SRv6 SID mapping. Then, the MPE forwards the packet to the SPE in SRv6 BE or SRv6 TE mode.

3. When the SPE receives the packet, it decapsulates the packet based on the SRv6 SID and forwards the packet to CE 2.

IP L3VPN over SRv6 FRR

IMPORTANT:

IP L3VPN over SRv6 FRR is supported only when the customer sites belong to VPNs.

IP L3VPN over SRv6 Fast Reroute (FRR) is applicable to a dualhomed scenario, as shown in Figure 3. By using static BFD to detect the primary link, FRR enables a PE to use the backup link when the primary link fails. The PE then selects a new optimal route, and uses the new optimal route to forward traffic.

IP L3VPN over SRv6 supports VPNv4 route backup for a VPNv4 route and VPNv6 route backup for a VPNv6 route.

Figure 3 Network diagram of VPNv4 route backup for a VPNv4 route

IPv4 L3VPN over SRv6 and IPv6 L3VPN over SRv6 use the same FRR mechanism. This section uses VPNv4 route backup for a VPNv4 route as an example to illustrate the mechanism.

As shown in Figure 3, configure FRR on the ingress node PE 1, and specify the backup next hop for VPN 1 as PE 3. When PE 1 receives a VPNv4 route to CE 2 from both PE 2 and PE 3, it uses the route from PE 2 as the primary link, and the route from PE 3 as the backup link.

Configure static BFD for public tunnels on PE 1 to detect the connectivity of the public tunnel from PE 1 to PE 2. When the tunnel PE 1—PE 2 operates correctly, traffic from CE 1 to CE 2 goes through the path CE 1—PE 1—PE 2—CE 2. When the tunnel fails, the traffic goes through the path CE 1—PE 1—PE 3—CE 2.

In this scenario, PE 1 is responsible for primary link detection and traffic switchover.

For more information about static BFD, see BFD configuration in High Availability Configuration Guide.

Restrictions and guidelines: IP L3VPN over SRv6 configuration

The device does not support End.DX4 or End.DX6 SIDs in the current software version.

IP L3VPN over SRv6 tasks at a glance

To configure IP L3VPN over SRv6, perform the following tasks:

1. Configuring a VPN instance and associating interfaces connected to CEs with the VPN instance

Perform this task on PEs. For more information, see MPLS L3VPN in MPLS Configuration Guide.

2. Configuring route exchange between a PE and a CE

Configure an IPv4 routing protocol (static routing, OSPF, IS-IS, EBGP, or IBGP) or an IPv6 routing protocol (IPv6 static routing, OSPFv3, IPv6 IS-IS, EBGP, or IBGP) to exchange routes between a PE and a CE

On the CE, configure an IPv4 or IPv6 routing protocol to advertise routes of the local site to the PE. On the PE, associate the routing protocol with the VPN instance. For more information about routing protocol configurations, see Layer 3—IP Routing Configuration Guide.

3. Configuring route exchange between PEs

a. Configuring an SRv6 SID

Perform this task to manually configure an End.DT4, End.DT6, End.DT46, End.DX4, or End.DX6 SID.

b. Applying a locator to a BGP VPN instance

BGP can advertise SRv6 SIDs through BGP routes only after you apply a locator to BGP.

c. Configuring PEs to exchange BGP VPNv4 or VPNv6 routes

d. Configuring IPv6 peers to exchange SRv6 SIDs

This feature enables PEs to exchange End.DT4, End.DT6, End.DT46, End.DX4, or End.DX6 SIDs through BGP VPNv4 or VPNv6 routes.

e. (Optional.) Configuring BGP VPNv4 or VPNv6 routes

4. Configuring the route recursion mode

5. Specifying a source address for the outer IPv6 header of SRv6-encapsulated packets

This feature specifies the source address of the outer IPv6 header for SRv6 packets that are delivered between two sites over the backbone network.

6. (Optional.) Configuring intercommunication for SRv6 and MPLS networks

¡ Configuring optimal route reorigination and advertisement

¡ Modifying BGP VPNv4 or VPNv6 routes

7. (Optional.) Enabling SRv6 VPN compatibility for a peer or peer group

8. (Optional.) Configuring IP L3VPN over SRv6 FRR

Configuring an SRv6 SID

Restrictions and guidelines

If PEs advertise BGP VPNv4 or VPNv6 routes to each other, you must specify a VPN instance when configuring an opcode.

Procedure

1. Enter system view.

system-view

2. Enable SRv6 and enter SRv6 view.

segment-routing ipv6

3. Configure 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 opcode. Perform one of the following tasks:

¡ Configure an End.DT4 SID.

opcode { opcode | hex hex-opcode } end-dt4 [ vpn-instance vpn-instance-name ]

The specified VPN instance must exist. An End.DT4 SID cannot be configured in different VPN instances.

¡ Configure an End.DT6 SID.

opcode { opcode | hex hex-opcode } end-dt6 [ vpn-instance vpn-instance-name ]

The specified VPN instance must exist. An End.DT6 SID cannot be configured in different VPN instances.

¡ Configure an End.DT46 SID.

opcode { opcode | hex hex-opcode } end-dt46 [ vpn-instance vpn-instance-name ]

The specified VPN instance must exist. An End.DT46 SID cannot be configured in different VPN instances.

Applying a locator to a BGP VPN instance

About this task

This feature is applicable to an IP L3VPN over SRv6 network with VPN sites. Use this feature in BGP-VPN IPv4 or IPv6 unicast address family view of a VPN instance to apply for SRv6 SIDs for the private network routes of the VPN instance.

Use this feature if the device will use End.DT4, End.DT6, End.DT46, End.DX4, or End.DX6 SIDs to deliver VPN traffic across sites.

Restrictions and guidelines

The VPN instance of the specified locator must be the same as the VPN instance of the private network. To specify a VPN instance for a locator, use the opcode end-dt4, opcode end-dt6, opcode end-dt46, opcode end-dx4, or opcode end-dx6 command in SRv6 locator view.

Prerequisites

Before you perform this task, you must create the specified locator.

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. Enter BGP-VPN IPv4 unicast address family view or BGP-VPN IPv6 unicast address family view.

¡ Enter BGP-VPN IPv4 unicast address family view.

address-family ipv4 [ unicast ]

¡ Enter BGP-VPN IPv6 unicast address family view.

address-family ipv6 [ unicast ]

5. Apply a locator to the BGP VPN instance.

segment-routing ipv6 locator locator-name [ auto-sid-disable ]

By default, no locator is applied to a BGP VPN instance.

Configuring PEs to exchange BGP VPNv4 or VPNv6 routes

Restrictions and guidelines

For more information about the commands in this section, see BGP in Layer 3—IP Routing Command Reference.

To ensure optimal route selection and SRv6 tunnel traffic forwarding, make sure a pair of PEs are not both IPv4 and IPv6 peers to each other.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Specify a remote PE as an IPv6 peer.

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

4. Specify a source interface (IPv6 address) for establishing TCP connections to an IPv6 peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } connect-interface interface-type interface-number

By default, BGP uses the output interface in the optimal route destined for a BGP peer or peer group as the source interface for establishing TCP connections.

5. Create the BGP VPNv4 or VPNv6 address family and enter its view.

¡ Create the BGP VPNv4 address family and enter its view.

address-family vpnv4

¡ Create the BGP VPNv6 address family and enter its view.

address-family vpnv6

6. Enable BGP to exchange VPNv4 or VPNv6 routing information with an IPv6 peer or peer group.

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

By default, BGP cannot exchange VPNv4 or VPNv6 routing information with an IPv6 peer or peer group.

Configuring IPv6 peers to exchange SRv6 SIDs

About this task

Perform this task to configure IPv6 peers to exchange SRv6 SID information through BGP VPNv4, VPNv6, IPv4 unicast, or IPv6 unicast routes.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Enable BGP to exchange SRv6 SID information with an IPv6 peer or peer group.

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

By default, BGP cannot exchange SRv6 SID information with an IPv6 peer or peer group.

Configuring BGP VPNv4 or VPNv6 routes

Restrictions and guidelines for BGP VPNv4 or VPNv6 route configuration

For more information about the commands in this section, see BGP in Layer 3—IP Routing Command Reference.

Controlling BGP VPNv4 or VPNv6 route advertisement and reception

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Set the maximum number of routes that BGP can receive from a peer or peer group.

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

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

5. Save all route updates from a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } keep-all-routes

By default, route updates from peers and peer groups are not saved.

Setting a preferred value for received BGP VPNv4 or VPNv6 routes

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Set a preferred value for routes received from a peer or peer group.

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

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

Configuring BGP VPNv4 or VPNv6 route reflection

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Configure the router as a route reflector (RR) and specify a peer or peer group as its client.

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

By default, no RR or client is configured.

5. (Optional.) Enable route reflection between clients.

reflect between-clients

By default, route reflection between clients is enabled.

6. (Optional.) Configure the cluster ID of the RR.

reflector cluster-id { cluster-id | ip-address }

By default, an RR uses its own router ID as the cluster ID.

7. (Optional.) Create an RR reflection policy.

rr-filter { ext-comm-list-number | ext-comm-list-name }

By default, an RR does not filter reflected routes.

8. (Optional.) Enable the RR to change the attributes of routes to be reflected.

reflect change-path-attribute

By default, the RR cannot change the attributes of routes to be reflected.

Configuring BGP VPNv4 or VPNv6 route attributes

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

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

5. Configure the AS_PATH attribute.

¡ Permit the local AS number to appear in routes from a peer or peer group and set the appearance times.

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

By default, the local AS number is not allowed in routes from a peer or peer group.

¡ Remove private AS numbers from the AS_PATH attribute of updates sent to an EBGP peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } public-as-only

By default, BGP updates sent to an EBGP peer or peer group can carry both public and private AS numbers.

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

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

By default, the COMMUNITY attribute is not advertised.

7. Advertise the Large community attribute to a peer or peer group.

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

By default, the Large community attribute is not advertised to a peer or peer group.

8. Configure the SoO attribute for a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } soo site-of-origin

By default, no SoO attribute is configured for a peer or peer group.

Configuring BGP VPNv4 or VPNv6 route distribution filtering policies

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Specify an ACL or IP prefix list to filter advertised BGP routes.

filter-policy { ipv4-acl-number | name ipv4-acl-name | prefix-list prefix-list-name } export [ protocol process-id ]

By default, no ACL or IP prefix list is specified to filter advertised BGP routes.

5. Specify an ACL or IP prefix list to filter received BGP routes.

filter-policy { ipv4-acl-number | name ipv4-acl-name | prefix-list prefix-list-name } import

By default, no ACL or IP prefix list is specified to filter received BGP routes.

6. Specify an IP prefix list to filter BGP routes for a peer or peer group.

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

By default, no IP prefix list is specified to filter BGP routes for a peer or peer group.

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

8. Enable route target filtering of received VPNv4 or VPNv6 routes.

policy vpn-target

By default, the route target filtering feature is enabled for received VPNv4 or VPNv6 routes. BGP adds an VPNv4 or VPNv6 route to the routing table only when the export route targets of the route match the local import route targets.

Configuring the BGP Additional Paths feature

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Configure the BGP Additional Paths capabilities.

peer { group-name | ipv6-address [ prefix-length ] } additional-paths { receive | send } *

By default, no BGP Additional Paths capabilities are configured.

5. Set the maximum number of Add-Path optimal routes that can be advertised to a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } advertise additional-paths best number

By default, only one Add-Path optimal route can be advertised to a peer or peer group.

6. (Optional.) Set the optimal route selection delay timer.

route-select delay delay-value

By default, the optimal route selection delay timer is 0 seconds, which indicates that optimal route selection is not delayed.

Configuring the route recursion mode

About this task

After a PE receives a customer packet destined for an SRv6 SID, it forwards the packet according to the route recursion mode.

· SRv6 BE mode—This mode is also called SID-based forwarding mode. In this mode, the PE first encapsulates the End.DT4, End.DT6, or End.DT46 SID into the packet. Then, the PE searches the IPv6 routing table based on the SID encapsulated in the packet to forward the packet.

· SRv6 TE mode—This mode is also called SRv6 TE policy-based forwarding mode. In this mode, the PE first searches for a matching SRv6 TE policy based on the packet attributes. Then, the PE adds an SRH to the packet. The SRH includes the End.DT4, End.DT6, or End.DT46 SID and the SID list of the SRv6 TE policy. Finally, the PE forwards the encapsulated packet through the SRv6 TE policy. For more information, see "Configuring SRv6 TE policies."

· SRv6 TE and SRv6 BE hybrid mode—In this mode, the PE preferentially uses the SRv6 TE mode to forward the packet. If no SRv6 TE policy is available for the packet, the PE forwards the packet in SRv6 BE mode.

Prerequisites

To use the SRv6 TE mode or the SRv6 TE and SRv6 BE hybrid mode, you must configure a tunnel policy and SRv6 TE policy. For more information, see tunnel policy configuration in MPLS Configuration Guide and "Configuring SRv6 TE policies."

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. Enter BGP-VPN IPv4 unicast address family view or BGP-VPN IPv6 unicast address family view.

¡ Enter BGP-VPN IPv4 unicast address family view.

address-family ipv4 [ unicast ]

¡ Enter BGP-VPN IPv6 unicast address family view.

address-family ipv6 [ unicast ]

5. Configure the route recursion mode.

segment-routing ipv6 { best-effort | traffic-engineer | traffic-engineer best-effort }

By default, a PE searches the IPv6 routing table based on the next hop of a matching route to forward traffic.

Specifying a source address for the outer IPv6 header of SRv6-encapsulated packets

Restrictions and guidelines

To ensure correct traffic forwarding in an IP L3VPN over SRv6 network with VPN or public network sites, you must specify a source address for the outer IPv6 header of SRv6-encapsulated packets.

You cannot specify a loopback address, link-local address, multicast address, or unspecified address as the source IPv6 address. You must specify an IPv6 address of the local device as the source IPv6 address, and make sure the IPv6 address has been advertised by a routing protocol. As a best practice, specify a loopback interface address of the local device as the source IPv6 address.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Specify a source address for the outer IPv6 header of SRv6-encapsulated packets.

encapsulation source-address ipv6-address [ ip-ttl ttl-value ]

By default, no source address is specified for the outer IPv6 header of SRv6-encapsulated packets.

Configuring optimal route reorigination and advertisement

About this task

Configure this feature on an MPE that connects the MPLS L3VPN and MPLS L3VPN over SRv6 networks.This feature enables the MPE to reoriginate the optimal BGP VPNv4 or VPNv6 routes for intercommunication between the MPLS and SRv6 networks.

With this feature, the MPE performs the following operations after receiving BGP VPNv4 or VPNv6 routes:

1. Matches the route targets of the routes with the import route targets of local VPN instances.

2. Reoriginates the optimal routes in the matching VPN instance. The optimal routes include the private network label or an SRv6 SID.

3. Advertises the reoriginated routes to VPNv4 or VPNv6 peers.

The reoriginated routes include the RD of the VPN instance. In addition, the route targets of the VPN instance are added to the routes based on the original routes.

Restrictions and guidelines

Configure all settings in this section on an MPE.

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. Enter BGP-VPN IPv4 unicast address family view or BGP-VPN IPv6 unicast address family view.

¡ Enter BGP-VPN IPv4 unicast address family view.

address-family ipv4 [ unicast ]

¡ Enter BGP-VPN IPv6 unicast address family view.

address-family ipv6 [ unicast ]

5. Configure the device to reoriginate the optimal routes in the VPN instance and advertise the reoriginated routes to VPNv4 or VPNv6 peers.

advertise route-reoriginate

By default, the device does not reoriginate the optimal routes in a VPN instance. The original VPNv4 or VPNv6 routes are advertised to VPNv4 or VPNv6 peers.

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

Modifying BGP VPNv4 or VPNv6 routes

About this task

Configure this feature on an MPE that connects the MPLS L3VPN and IP L3VPN over SRv6 networks.This feature enables the MPE to modify BGP VPNv4 or VPNv6 route information for intercommunication between the MPLS and SRv6 networks.

After you configure this feature on an MPE, the MPE performs the following operations after receiving BGP VPNv4 or VPNv6 routes from the MPLS L3VPN network:

1. Matches the route targets of the routes with the import route targets of local VPN instances.

2. Replaces the RD and route targets of the routes with those of the matching local VPN instance. In addition, the MPE adds an SRv6 SID to the routes and maps the SRv6 SID of the routes to the private label of the routes.

3. Advertises the reoriginated routes to the SRv6 network.

After you configure this feature on an MPE, the MPE performs the following operations after receiving BGP VPNv4 or VPNv6 routes from the SRv6 network:

1. Matches the route targets of the routes with the import route targets of local VPN instances.

2. Replaces the RD and route targets of the routes with those of the matching local VPN instance. In addition, the MPE adds an MPLS label to the routes and maps the private label of the routes to the SRv6 SID of the routes.

3. Advertises the reoriginated routes to the MPLS L3VPN network.

Restrictions and guidelines

All settings in this section are configured on an MPE.

In addition to the settings in this section, you also need to configure other settings on the UPEs, MPE, and SPE depending on the network type. If the network type is MPLS, configure basic MPLS L3VPN settings. If the network type is SRv6, configure basic MPLS L3VPN over SRv6 settings.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Enable the device to reoriginate BGP VPNv4 or VPNv6 routes based on the BGP VPNv4 or VPNv6 routes received from a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } re-originated [ replace-rt ]

By default, the device does not reoriginate BGP VPNv4 or VPNv6 routes based on received BGP VPNv4 or VPNv6 routes.

5. (Optional.) Enable the device to advertise original BGP VPNv4 or VPNv6 routes to a peer or peer group.

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

By default, the device advertises only reoriginated BGP VPNv4 or VPNv6 routes to peers and peer groups after the peer re-originated command is executed.

6. (Optional.) Suppress advertisement of reoriginated BGP VPNv4 or VPNv6 routes to a peer or peer group.

peer { group-name | ipv4-address [ mask-length ] | ipv6-address [ prefix-length ] } suppress re-originated

By default, the device advertises reoriginated BGP VPNv4 or VPNv6 routes to peers and peer groups after the peer re-originated command is executed.

Enabling SRv6 VPN compatibility for a peer or peer group

About this task

In an IP L3VPN over SRv6 network, the peer PE might from other vendors. Such a device might use a different value for the SRv6 L3 Service Type field (SRv6 L3VPN service type) in BGP updates for advertising SRv6 SIDs. As a result, route exchange might fail, affecting packet forwarding. To resolve this issue, you can perform this task to enable interoperability between Comware devices and devices from other vendors.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Enable SRv6 VPN compatibility for a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } srv6-vpn compatible

By default, SRv6 VPN compatibility is disabled for a peer or peer group.

Configuring IP L3VPN over SRv6 FRR

About this task

This task is applicable to an IP L3VPN over SRv6 network.

MPLS L3VPN over SRv6 FRR enables the device to calculate backup routes for all routes of a VPN instance to reduce the traffic interruption caused by link or device failures on the backbone. If the device learns two unequal-cost routes destined for the same network from different peers, the optimal route is backed up by the other route. When the optimal route becomes unavailable, the device uses the backup route to forward traffic. At the same time, the device calculates a new optimal route and then uses it to direct traffic forwarding.

Restrictions and guidelines

This feature might cause routing loops in certain conditions. Make sure you are fully aware of this feature when you use it on a live network.

Procedure

1. Enter system view.

system-view

2. Configure static BFD.

bfd static session-name [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] source-ipv6 ipv6-address [ discriminator local local-value remote remote-value ] [ track-interface interface-type interface-number ] ]

3. Return to system view.

quit

4. Enter BGP instance view.

bgp as-number [ instance instance-name ]

5. Configure BGP FRR to use BFD to detect next hop connectivity for the primary route.

primary-path-detect bfd echo

By default, BGP FRR uses ARP to detect the connectivity to the next hop of the primary route.

For more information about this command, see BGP commands in Layer 3—IP Routing Command Reference.

6. Enter BGP-VPN IPv4 unicast address family view, BGP VPNv4 address family view, BGP-VPN IPv6 unicast address family view, or BGP VPNv6 address family view.

¡ Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view:

ip vpn-instance vpn-instance-name

address-family ipv4 [ unicast ]

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:

ip vpn-instance vpn-instance-name

address-family ipv6 [ unicast ]

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

7. Enable FRR for the address family.

pic

By default, FRR is disabled for a BGP address family.

For more information about this command, see BGP commands in Layer 3—IP Routing Command Reference.

Display and maintenance commands for IP L3VPN over SRv6

Resetting BGP sessions

For BGP setting changes to take effect, you must reset or soft-reset BGP sessions. Soft-resetting BGP sessions updates BGP routing information without tearing down the BGP sessions. Resetting BGP sessions updates BGP routing information by tearing down and re-establishing the BGP sessions. Soft-reset requires that both the local router and the peer support ROUTE-REFRESH messages.

Execute the commands in this section in user view. For more information about the commands, see BGP in Layer 3—IP Routing Command Reference.

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Task	Command
Soft-reset BGP sessions of the BGP VPNv4 address family.	refresh bgp [ instance instance-name ] ipv6-address [ prefix-length ] { export \| import } vpnv4
Reset BGP sessions of the BGP VPNv4 address family.	reset bgp [ instance instance-name ] ipv6-address [ prefix-length ] vpnv4

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Displaying and maintaining the running status of IP L3VPN over SRv6 VPN

Execute display commands in any view and reset commands in user view.

For more information about the commands in this section, see BGP in Layer 3—IP Routing Command Reference.

Task	Command
Display BGP VPNv4 peer or peer group information.	display bgp [ instance instance-name ] peer vpnv4 { ipv6-address prefix-length \| ipv6-address { log-info \| verbose } }
Display BGP VPNv6 peer or peer group information.	display bgp [ instance instance-name ] peer vpnv6 [ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length \| { ipv6-address \| group-name group-name } log-info \| [ ipv6-address ] verbose ]
Display BGP update group information for VPNv4 address family.	display bgp [ instance instance-name ] update-group vpnv4 ipv6-address
Display BGP update group information for VPNv6 address family.	display bgp [ instance instance-name ] update-group vpnv6 [ vpn-instance vpn-instance-name ] [ ipv6-address ]
Clear flap statistics for BGP VPNv4 routes.	reset bgp [ instance instance-name ] flap-info vpnv4 [ ipv4-address [ mask \| mask-length ] \| as-path-acl as-path-acl-number \| peer ipv6-address [ prefix-length ] ]

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IP L3VPN over SRv6 configuration examples

Example: Configuring IP L3VPN over SRv6 BE

Network configuration

As shown in Figure 4, the backbone network is an IPv6 network, and VPN 1 is an IPv4 network. Deploy IP L3VPN over SRv6 between PE 1 and PE 2 and use an SRv6 tunnel to transmit VPNv4 traffic between the PEs.

· Configure EBGP to exchange VPN routing information between the CEs and PEs.

· Configure IPv6 IS-IS on the PEs in the same AS to realize IPv6 network connectivity.

· Configure MP-IBGP to exchange VPNv4 routing information between the PEs.

Figure 4 Network diagram

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Table 1 Interface and IP address assignment

Device	Interface	IP address	Device	Interface	IP address
CE 1	XGE2/0/0	10.1.1.2/24	PE 2	Loop0	3::3/128
PE 1	Loop0	1::1/128		XGE2/0/0	10.2.1.1/24
	XGE2/0/0	10.1.1.1/24		XGE2/0/1	2002::1/96
	XGE2/0/1	2001::1/96	CE 2	XGE2/0/0	10.2.1.2/24
P	Loop0	2::2/128
	XGE2/0/0	2001::2/96
	XGE2/0/1	2002::2/96

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Procedure

1. Configure IPv6 IS-IS on the PEs and device P for network connectivity between the devices:

# Configure PE 1.

<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 2/0/1

[PE1-Ten-GigabitEthernet2/0/1] ipv6 address 2001::1 96

[PE1-Ten-GigabitEthernet2/0/1] isis ipv6 enable

[PE1-Ten-GigabitEthernet2/0/1] quit

# Configure P.

<P> system-view

[P] isis

[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

[P-LoopBack0] quit

[P] interface ten-gigabitethernet 2/0/0

[P-Ten-GigabitEthernet2/0/0] ipv6 address 2001::2 96

[P-Ten-GigabitEthernet2/0/0] isis ipv6 enable

[P-Ten-GigabitEthernet2/0/0] quit

[P] interface ten-gigabitethernet 2/0/1

[P-Ten-GigabitEthernet2/0/1] ipv6 address 2002::2 96

[P-Ten-GigabitEthernet2/0/1] isis ipv6 enable

[P-Ten-GigabitEthernet2/0/1] quit

# Configure PE 2.

<PE2> system-view

[PE2] isis

[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

[PE2-LoopBack0] quit

[PE2] interface ten-gigabitethernet 2/0/1

[PE2-Ten-GigabitEthernet2/0/1] ipv6 address 2002::1 96

[PE2-Ten-GigabitEthernet2/0/1] isis ipv6 enable

[PE2-Ten-GigabitEthernet2/0/1] quit

# Verify that PE 1, P, and PE 2 have established IPv6 IS-IS neighbor relationships and the neighbor state is up.

[PE1] display isis peer

[P] display isis peer

[PE2] display isis peer

# Verify that PE 1 and PE 2 each learn a route destined for the loopback interface of each other.

[PE1] display isis route ipv6

[PE2] display isis route ipv6

2. Configure VPN instance settings on PE 1 and PE 2 and verify that each CE can access its local PE:

# Configure PE 1.

[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 2/0/0

[PE1-Ten-GigabitEthernet2/0/0] ip binding vpn-instance vpn1

[PE1-Ten-GigabitEthernet2/0/0] ip address 10.1.1.1 24

[PE1-Ten-GigabitEthernet2/0/0] quit

# Configure PE 2.

[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 2/0/0

[PE2-Ten-GigabitEthernet2/0/0] ip binding vpn-instance vpn1

[PE2-Ten-GigabitEthernet2/0/0] ip address 10.2.1.1 24

[PE2-Ten-GigabitEthernet2/0/0] quit

# Configure IP addresses for the interfaces on the CEs, as shown in Figure 4. (Details not shown.)

# Display VPN instance settings on each PE. This step uses PE 1 as an example.

[PE1] display ip vpn-instance

Total VPN-Instances configured : 1

Total IPv4 VPN-Instances configured : 1

Total IPv6 VPN-Instances configured : 1

VPN-Instance Name RD Address family Create time

vpn1 100:1 IPv4/IPv6 2019/08/12 13:59:39

# Verify that each PE can ping its local CE. This step uses PE 1 and CE 1 as an example.

[PE1] ping -vpn-instance vpn1 10.1.1.2

Ping 10.1.1.2 (10.1.1.2): 56 data bytes, press CTRL+C to break

56 bytes from 10.1.1.2: icmp_seq=0 ttl=255 time=2.000 ms

56 bytes from 10.1.1.2: icmp_seq=1 ttl=255 time=0.000 ms

56 bytes from 10.1.1.2: icmp_seq=2 ttl=255 time=1.000 ms

56 bytes from 10.1.1.2: icmp_seq=3 ttl=255 time=0.000 ms

56 bytes from 10.1.1.2: icmp_seq=4 ttl=255 time=0.000 ms

--- Ping statistics for 10.1.1.2 in VPN instance vpn1 ---

5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss

round-trip min/avg/max/std-dev = 0.000/0.600/2.000/0.800 ms

3. Set up an EBGP peer relationship between each PE and its local CE and distribute VPN routes to EBGP:

# Configure CE 1.

<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

# Configure CE 2 in the same way as CE 1 is configured. (Details not shown.)

# Configure PE 1.

[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

# Configure PE 2 in the same way PE 1 is configured. (Details not shown.)

# Verify that the PEs have established BGP peer relationships with their local CEs and the peers are in established state.

[PE1] display bgp peer ipv4 vpn-instance

[PE2] display bgp peer ipv4 vpn-instance

4. Set up an MP-IBGP peer relationship between PE 1 and PE 2:

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp-default] peer 3::3 as-number 100

[PE1-bgp-default] peer 3::3 connect-interface loopback 0

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 3::3 enable

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] quit

# Configure PE 2.

[PE2] bgp 100

[PE2-bgp-default] peer 1::1 as-number 100

[PE2-bgp-default] peer 1::1 connect-interface loopback 0

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 enable

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] quit

# Verify that the PEs have established a BGP peer relationship and the peers are in established state.

[PE1] display bgp peer vpnv4

[PE2] display bgp peer vpnv4

5. Specify a source address for the outer IPv6 header of SRv6-encapsulated IP L3VPN packets on PE 1 and PE 2:

# Configure PE 1.

[PE1] segment-routing ipv6

[PE1-segment-routing-ipv6] encapsulation source-address 1::1

# Configure PE 2.

[PE2] segment-routing ipv6

[PE2-segment-routing-ipv6] encapsulation source-address 3::3

6. Configure the destination address (End.DT4 SID) of the outer IPv6 header for SRv6-encapsulated IP L3VPN packets:

# Configure PE 1.

[PE1-segment-routing-ipv6] locator aaa ipv6-prefix 1:2::1:0 96 static 8

[PE1-segment-routing-ipv6-locator-aaa] quit

[PE1-segment-routing-ipv6] 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 PE 2.

[PE2-segment-routing-ipv6] locator bbb ipv6-prefix 6:5::1:0 96 static 8

[PE2-segment-routing-ipv6-locator-bbb] quit

[PE2-segment-routing-ipv6] 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

# Verify that the PEs have distributed the End.DT4 SIDs to the routing table and generated SRv6 routes. This step uses PE 1 as an example.

[PE1] display ipv6 routing-table protocol srv6

Summary count : 1

SRv6 Routing table status : <Active>

Summary count : 1

Destination: 1:2::101/128 Protocol : SRv6

NextHop : ::1 Preference: 4

Interface : InLoop0 Cost : 0

SRv6 Routing table status : <Inactive>

Summary count : 0

7. Add End.DT4 SIDs to private network routes on PE 1 and PE 2:

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp-default] ip vpn-instance vpn1

[PE1-bgp-default-vpn1] address-family ipv4 unicast

[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

# Configure PE 2.

[PE2] bgp 100

[PE2-bgp-default] ip vpn-instance vpn1

[PE2-bgp-default-vpn1] address-family ipv4 unicast

[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

8. Enable IPv6 peers on the PEs to exchange End.DT4 SIDs and enable the SID-route-recursion feature:

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 3::3 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 best-effort

[PE1-bgp-default-ipv4-vpn1] quit

[PE1-bgp-default-vpn1] quit

[PE1-bgp-default] quit

# Configure PE 2.

[PE2] bgp 100

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 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 best-effort

[PE2-bgp-default-ipv4-vpn1] quit

[PE2-bgp-default-vpn1] quit

[PE2-bgp-default] quit

# Display BGP VPNv4 routing information on each PE and verify that the routes advertised by the PEs have the SID attribute. This step uses PE 1 as an example.

[PE1] display bgp routing-table vpnv4 10.2.1.0

BGP local router ID: 1.1.1.1

Local AS number: 100

Route distinguisher: 100:1(vpn1)

Total number of routes: 1

Paths: 1 available, 1 best

BGP routing table information of 10.2.1.0/24:

From : 3::3 (3.3.3.3)

Rely nexthop : FE80::2A96:34FF:FE9D:216

Original nexthop: 3::3

Out interface : Ten-GigabitEthernet2/0/1

Route age : 00h14m23s

OutLabel : 3

Ext-Community : <RT: 111:1>

RxPathID : 0x0

TxPathID : 0x0

PrefixSID : End.DT4 SID <6:5::101>

AS-path : 65420

Origin : incomplete

Attribute value : MED 0, localpref 100, pref-val 0

State : valid, internal, best

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : NULL

Rely tunnel IDs : N/A

Verifying the configuration

# Display IPv4 routing table information on the PEs and verify that each PE has a route destined for the remote CE and the next hop of the route is the End.DT4 SID of the route. This step uses PE 1 as an example.

[PE1] display ip routing-table vpn-instance vpn1

Destinations : 11 Routes : 11

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

10.1.1.0/24 Direct 0 0 10.1.1.1 XGE2/0/0

10.1.1.0/32 Direct 0 0 10.1.1.1 XGE2/0/0

10.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

10.1.1.255/32 Direct 0 0 10.1.1.1 XGE2/0/0

10.2.1.0/24 BGP 255 0 6:5::1:0 XGE2/0/1

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

# Verify that CE 1 and CE 2 can ping each other. (Details not shown.)

Example: Configuring IPv4 L3VPN HoVPN over MPLS-to-SRv6

Network configuration

As shown in Figure 5, the network between the UPE and MPE is an MPLS network and the network between the MPE and SPE is an SRv6 network. Configure HoVPN to permit users in the same VPN instance to communicate with each other across the MPLS and SRv6 networks.

Figure 5 Network diagram

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Device	Interface	IP address	Device	Interface	IP address
CE 1	XGE2/0/0	10.1.1.2/24	MPE	Loop0	2.2.2.2/32 2::2/128
CE 2	XGE2/0/0	10.2.1.2/24		XGE2/0/0	11.1.1.2/24
UPE	Loop0	1.1.1.1/32		XGE2/0/1	100::1/96
	XGE2/0/0	10.1.1.1/24	SPE	Loop0	3::3/128
	XGE2/0/1	11.1.1.1/24		XGE2/0/0	10.2.1.1/24
				XGE2/0/1	100::2/96

Procedure

1. Configure CE 1:

# Establish EBGP peer relationship with the UPE and import VPN routes.

<CE1> system-view

[CE1] bgp 101

[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 the UPE:

# Configure MPLS basic capability and MPLS LDP capability.

<UPE> system-view

[UPE] mpls lsr-id 1.1.1.1

[UPE] mpls ldp

[UPE-ldp] quit

# Configure IS-IS for backbone network communication.

[UPE] isis 1

[UPE-isis-1] is-level level-1

[UPE-isis-1] cost-style wide

[UPE-isis-1] network-entity 10.1111.1111.1111.00

[UPE-isis-1] quit

[UPE] interface loopback 0

[UPE-LoopBack0] ip address 1.1.1.1 32

[UPE-LoopBack0] isis enable 1

[UPE-LoopBack0] quit

[UPE] interface ten-gigabitethernet 2/0/1

[UPE-Ten-GigabitEthernet2/0/1] ip address 11.1.1.1 24

[UPE-Ten-GigabitEthernet2/0/1] isis enable 1

[UPE-Ten-GigabitEthernet2/0/1] mpls enable

[UPE-Ten-GigabitEthernet2/0/1] mpls ldp enable

[UPE-Ten-GigabitEthernet2/0/1] quit

# Configure a VPN instance for CE 1 to access the UPE.

[UPE] ip vpn-instance vpn1

[UPE-vpn-instance-vpn1] route-distinguisher 100:1

[UPE-vpn-instance-vpn1] vpn-target 111:1

[UPE-vpn-instance-vpn1] quit

[UPE] interface ten-gigabitethernet 2/0/0

[UPE-Ten-GigabitEthernet2/0/0] ip binding vpn-instance vpn1

[UPE-Ten-GigabitEthernet2/0/0] ip address 10.1.1.1 24

[UPE-Ten-GigabitEthernet2/0/0] quit

# Establish EBGP peer relationship with CE 1 and import VPN routes.

[UPE] bgp 100

[UPE-bgp-default] router-id 1.1.1.1

[UPE-bgp-default] ip vpn-instance vpn1

[UPE-bgp-default-vpn1] peer 10.1.1.2 as-number 101

[UPE-bgp-default-vpn1] address-family ipv4 unicast

[UPE-bgp-default-ipv4-vpn1] peer 10.1.1.2 enable

[UPE-bgp-default-ipv4-vpn1] import-route direct

[UPE-bgp-default-ipv4-vpn1] quit

[UPE-bgp-default-vpn1] quit

# Establish MP-IBGP peer relationship with the MPE.

[UPE-bgp-default] peer 2.2.2.2 as-number 100

[UPE-bgp-default] peer 2.2.2.2 connect-interface loopback 0

[UPE-bgp-default] address-family vpnv4

[UPE-bgp-default-vpnv4] peer 2.2.2.2 enable

[UPE-bgp-default-vpnv4] quit

[UPE-bgp-default] quit

3. Configure the MPE:

# Configure MPLS basic capability and MPLS LDP capability.

<MPE> system-view

[MPE] mpls lsr-id 2.2.2.2

[MPE] mpls ldp

[MPE-ldp] quit

# Configure IS-IS for backbone network communication.

[MPE] isis 1

[MPE-isis-1] is-level level-1

[MPE-isis-1] cost-style wide

[MPE-isis-1] network-entity 10.2222.2222.2222.00

[MPE-isis-1] address-family ipv6 unicast

[MPE-isis-1-ipv6] quit

[MPE-isis-1] quit

[MPE] interface loopback 0

[MPE-LoopBack0] ip address 2.2.2.2 32

[MPE-LoopBack0] ipv6 address 2::2 128

[MPE-LoopBack0] isis enable 1

[MPE-LoopBack0] isis ipv6 enable 1

[MPE-LoopBack0] quit

[MPE] interface ten-gigabitethernet 2/0/0

[MPE-Ten-GigabitEthernet2/0/0] ip address 11.1.1.2 24

[MPE-Ten-GigabitEthernet2/0/0] isis enable 1

[MPE-Ten-GigabitEthernet2/0/0] mpls enable

[MPE-Ten-GigabitEthernet2/0/0] mpls ldp enable

[MPE-Ten-GigabitEthernet2/0/0] quit

[MPE] interface ten-gigabitethernet 2/0/1

[MPE-Ten-GigabitEthernet2/0/1] ipv6 address 100::1 96

[MPE-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[MPE-Ten-GigabitEthernet2/0/1] quit

# Configure a VPN instance.

[MPE] ip vpn-instance vpn2

[MPE-vpn-instance-vpn1] route-distinguisher 200:1

[MPE-vpn-instance-vpn1] vpn-target 111:1

[MPE-vpn-instance-vpn1] quit

# Establish MP-IBGP peer relationship with the UPE and SPE.

[MPE] bgp 100

[MPE-bgp-default] router-id 2.2.2.2

[MPE-bgp-default] peer 1.1.1.1 as-number 100

[MPE-bgp-default] peer 1.1.1.1 connect-interface LoopBack0

[MPE-bgp-default] peer 3::3 as-number 102

[MPE-bgp-default] peer 3::3 connect-interface LoopBack0

[MPE-bgp-default] address-family vpnv4

[MPE-bgp-default-vpnv4] peer 1.1.1.1 enable

[MPE-bgp-default-vpnv4] peer 3::3 enable

# Specify a UPE.

[MPE-bgp-default-vpnv4] peer 1.1.1.1 upe

[MPE-bgp-default-vpnv4] peer 1.1.1.1 next-hop-local

[MPE-bgp-default-vpnv4] quit

# Configure optimal route reorigination and advertisement for intercommunication between the MPLS L3VPN network and IP L3VPN over SRv6 network.

[MPE-bgp-default] ip vpn-instance vpn2

[MPE-bgp-default-vpn2] address-family ipv4 unicast

[MPE-bgp-default-ipv4-vpn2] advertise route-reoriginate

[MPE-bgp-default-ipv4-vpn2] quit

[MPE-bgp-default-vpn2] quit

[MPE-bgp-default] quit

# Enable the MPE to send routing information matching a routing policy to the UPE. The route of CE 2 can be sent to the UPE.

[MPE] ip prefix-list hovpn index 10 permit 10.2.1.0 24

[MPE] route-policy hovpn permit node 0

[MPE-route-policy-hovpn-0] if-match ip address prefix-list hovpn

[MPE-route-policy-hovpn-0] quit

[MPE] bgp 100

[MPE-bgp-default] address-family vpnv4

[MPE-bgp-default-vpnv4] peer 1.1.1.1 upe route-policy hovpn export

[MPE-bgp-default-vpnv4] quit

[MPE-bgp-default] quit

# Configure L3VPN over SRv6 BE.

[MPE] segment-routing ipv6

[MPE-segment-routing-ipv6] encapsulation source-address 2::2

[MPE-segment-routing-ipv6] locator hovpn ipv6-prefix 42:1:: 64 static 32

[MPE-segment-routing-ipv6-locator-hovpn] quit

[MPE-segment-routing-ipv6] quit

[MPE] bgp 100

[MPE-bgp-default] address-family vpnv4

[MPE-bgp-default-vpnv4] peer 3::3 prefix-sid

[MPE-bgp-default-vpnv4] quit

[MPE-bgp-default] ip vpn-instance vpn2

[MPE-bgp-default-vpn2] address-family ipv4 unicast

[MPE-bgp-default-ipv4-vpn2] segment-routing ipv6 best-effort

[MPE-bgp-default-ipv4-vpn2] segment-routing ipv6 locator hovpn

[MPE-bgp-default-ipv4-vpn2] quit

[MPE-bgp-default-vpn2] quit

[MPE-bgp-default] quit

[MPE] isis 1

[MPE-isis-1] address-family ipv6 unicast

[MPE-isis-1-ipv6] segment-routing ipv6 locator hovpn

[MPE-isis-1-ipv6] quit

[MPE-isis-1] quit

4. Configure the SPE:

# Configure IPv6 IS-IS for backbone network communication.

<SPE> system-view

[SPE] isis 1

[SPE-isis-1] is-level level-1

[SPE-isis-1] cost-style wide

[SPE-isis-1] network-entity 10.3333.3333.3333.00

[SPE-isis-1] address-family ipv6 unicast

[SPE-isis-1-ipv6] quit

[SPE-isis-1] quit

[SPE] interface loopback 0

[SPE-LoopBack0] ipv6 address 3::3 128

[SPE-LoopBack0] isis ipv6 enable 1

[SPE-LoopBack0] quit

[SPE] interface ten-gigabitethernet 2/0/1

[SPE-Ten-GigabitEthernet2/0/1] ipv6 address 100::2 96

[SPE-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[SPE-Ten-GigabitEthernet2/0/1] quit

# Configure a VPN instance for CE 2 to access the SPE.

[SPE] ip vpn-instance vpn1

[SPE-vpn-instance-vpn1] route-distinguisher 100:1

[SPE-vpn-instance-vpn1] vpn-target 111:1

[SPE-vpn-instance-vpn1] quit

[SPE] interface ten-gigabitethernet 2/0/0

[SPE-Ten-GigabitEthernet2/0/0] ip binding vpn-instance vpn1

[SPE-Ten-GigabitEthernet2/0/0] ip address 10.2.1.1 24

[SPE-Ten-GigabitEthernet2/0/0] quit

# Establish EGFP peer relationship with CE 2 and import VPN routes.

[SPE] bgp 100

[SPE-bgp-default] router-id 3.3.3.3

[SPE-bgp-default] ip vpn-instance vpn1

[SPE-bgp-default-vpn1] peer 10.2.1.2 as-number 102

[SPE-bgp-default-vpn1] address-family ipv4 unicast

[SPE-bgp-default-ipv4-vpn1] peer 10.2.1.2 enable

[SPE-bgp-default-ipv4-vpn1] import-route direct

[SPE-bgp-default-ipv4-vpn1] quit

[SPE-bgp-default-vpn1] quit

# Establish MP-IBGP peer relationship with the MPE.

[SPE] bgp 100

[SPE-bgp-default] peer 2::2 as-number 100

[SPE-bgp-default] peer 2::2 connect-interface loopback 0

[SPE-bgp-default] address-family vpnv4

[SPE-bgp-default-vpnv4] peer 2::2 enable

[SPE-bgp-default-vpnv4] quit

[SPE-bgp-default] quit

# Configure L3VPN over SRv6 BE.

[SPE] segment-routing ipv6

[SPE-segment-routing-ipv6] encapsulation source-address 3::3

[SPE-segment-routing-ipv6] locator hovpn ipv6-prefix 43:1:: 64 static 32

[SPE-segment-routing-ipv6-locator-hovpn] quit

[SPE-segment-routing-ipv6] quit

[SPE] bgp 100

[SPE-bgp-default] address-family vpnv4

[SPE-bgp-default-vpnv4] peer 2::2 prefix-sid

[SPE-bgp-default-vpnv4] quit

[SPE-bgp-default] ip vpn-instance vpn1

[SPE-bgp-default-vpn1] address-family ipv4 unicast

[SPE-bgp-default-ipv4-vpn1] segment-routing ipv6 best-effort

[SPE-bgp-default-ipv4-vpn1] segment-routing ipv6 locator hovpn

[SPE-bgp-default-ipv4-vpn1] quit

[SPE-bgp-default-vpn1] quit

[SPE-bgp-default] quit

[SPE] isis 1

[SPE-isis-1] address-family ipv6 unicast

[SPE-isis-1-ipv6] segment-routing ipv6 locator hovpn

[SPE-isis-1-ipv6] quit

[SPE-isis-1] quit

5. Configure CE 2:

# Establish EBGP peer relationship with the SPE and import VPN routes.

<CE2> system-view

[CE2] bgp 102

[CE2-bgp-default] peer 10.2.1.1 as-number 100

[CE2-bgp-default] address-family ipv4 unicast

[CE2-bgp-default-ipv4] peer 10.2.1.1 enable

[CE2-bgp-default-ipv4] import-route direct

[CE2-bgp-default-ipv4] quit

[CE2-bgp-default] quit

Verifying the configuration

# On MPE, verify that the routes destined for CE 2 and CE 1 have established SRv6 SID and MPLS label mappings.

[MPE] display bgp routing-table vpnv4 10.2.1.0 24

BGP local router ID: 2.2.2.2

Local AS number: 100

Route distinguisher: 100:1

Total number of routes: 1

Paths: 1 available, 1 best

BGP routing table information of 10.2.1.0/24:

From : 3::3 (3.3.3.3)

Rely nexthop : FE80::9885:31FF:FE87:317

Original nexthop: 3::3

Out interface : Ten-GigabitEthernet2/0/1

Route age : 03h16m43s

OutLabel : 3

Ext-Community : <RT: 111:1>

RxPathID : 0x0

TxPathID : 0x0

PrefixSID : End.DT4 SID <43:1::1:0:2>

AS-path : (null)

Origin : incomplete

Attribute value : MED 0, localpref 100, pref-val 0

State : valid, internal, best

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : NULL

Rely tunnel IDs : N/A

Route distinguisher: 200:1(vpn2)

Total number of routes: 1

Paths: 1 available, 1 best

BGP routing table information of 10.2.1.0/24:

From : 3::3 (3.3.3.3)

Rely nexthop : FE80::9885:31FF:FE87:317

Original nexthop: 3::3

Out interface : Ten-GigabitEthernet2/0/1

Route age : 03h16m43s

OutLabel : 3

Ext-Community : <RT: 111:1>

RxPathID : 0x0

TxPathID : 0x0

PrefixSID : End.DT4 SID <43:1::1:0:2>

AS-path : (null)

Origin : incomplete

Attribute value : MED 0, localpref 100, pref-val 0

State : valid, internal, best, remoteredist, reoriginated

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : NULL

Rely tunnel IDs : N/A

[MPE] display bgp routing-table vpnv4 10.1.1.0 24

BGP local router ID: 2.2.2.2

Local AS number: 100

Route distinguisher: 100:1

Total number of routes: 1

Paths: 1 available, 1 best

BGP routing table information of 10.1.1.0/24:

From : 1.1.1.1 (1.1.1.1)

Rely nexthop : 11.1.1.1

Original nexthop: 1.1.1.1

Out interface : Ten-GigabitEthernet2/0/0

Route age : 00h44m22s

OutLabel : 600126

Ext-Community : <RT: 111:1>

RxPathID : 0x0

TxPathID : 0x0

AS-path : (null)

Origin : incomplete

Attribute value : MED 0, localpref 100, pref-val 0

State : valid, internal, best

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : NULL

Rely tunnel IDs : 3

Route distinguisher: 200:1(vpn2)

Total number of routes: 1

Paths: 1 available, 1 best

BGP routing table information of 10.1.1.0/24:

From : 1.1.1.1 (1.1.1.1)

Rely nexthop : 11.1.1.1

Original nexthop: 1.1.1.1

Out interface : Ten-GigabitEthernet2/0/0

Route age : 00h44m22s

OutLabel : 600126

Ext-Community : <RT: 111:1>

RxPathID : 0x0

TxPathID : 0x0

PrefixSID : End.DT4 SID <42:1::1:0:2>

AS-path : (null)

Origin : incomplete

Attribute value : MED 0, localpref 100, pref-val 0

State : valid, internal, best, remoteredist, reoriginated

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : NULL

Rely tunnel IDs : 3

# Verify that CE 1 and CE 2 can ping each other. (Details not shown.)

07-Segment Routing Configuration Guide

About IP L3VPN over SRv6

SRv6 BE mode

SRv6 TE mode

SRv6 TE and SRv6 BE hybrid mode

IP L3VPN over SRv6 tasks at a glance

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Prerequisites

Procedure

Restrictions and guidelines

Procedure

About this task

Procedure

About this task

Prerequisites

Procedure

Specifying a source address for the outer IPv6 header of SRv6-encapsulated packets

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Procedure

About this task

Restrictions and guidelines

Procedure

Display and maintenance commands for IP L3VPN over SRv6

Network configuration

Procedure

Verifying the configuration

Network configuration

Procedure

Verifying the configuration

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