BGP-4 can carry routing information for IPv4 only. IETF defined multiprotocol BGP extensions to carry routing information for multiple network layer protocols.

For a network, the multicast topology might be different from the unicast topology. To meet the requirement, the multiprotocol BGP extensions enable BGP to carry the unicast Network Layer Reachability Information (NLRI) and multicast NLRI separately, and the multicast NLRI performs reverse path forwarding (RPF) exclusively. In this way, route selection for a destination through the unicast routing table and through the multicast routing table will have different results, ensuring normal unicast and multicast routing.

Multi-protocol BGP is defined in RFC 2858 (Multiprotocol Extensions for BGP-4).

Multi-protocol BGP for IP multicast is referred to as Multicast BGP (MBGP) for short.

NOTE:

· This document covers configuration tasks related to multiprotocol BGP for IP multicast only. For more information about BGP, see Layer 3—IP Routing Configuration Guide.

· For more information about RPF, see the chapter “Configuring multicast routing and forwarding.”

Protocols and standards

· RFC2858, Multiprotocol Extensions for BGP-4

· RFC3392, Capabilities Advertisement with BGP-4

· draft-ietf-idmr-bgp-mcast-attr-00, BGP Attributes for Multicast Tree Construction

· RFC4271, A Border Gateway Protocol 4 (BGP-4)

· RFC5291, Outbound Route Filtering Capability for BGP-4

· RFC5292, Address-Prefix-Based Outbound Route Filter for BGP-4

MBGP configuration task list

Complete the following tasks to configure MBGP:

Task		Remarks
Configuring MBGP basic functions		Required
Controlling route advertisement and reception	Configuring MBGP route redistribution	Optional
	Configure default route redistribution into MBGP	Optional
	Configuring MBGP route summarization	Optional
	Advertising a default route to an IPv4 MBGP peer or peer group	Optional
	Configuring outbound MBGP route filtering	Optional
	Configuring inbound MBGP route filtering	Optional
	Configuring MBGP route dampening	Optional
Configuring MBGP route attributes	Configuring MBGP route preferences	Optional
	Configuring the default local preference
	Configuring the MED attribute
	Configuring the next hop attribute
	Configuring the AS-PATH attribute
Tuning and optimizing MBGP networks	Configuring MBGP soft reset	Optional
	Enabling the MBGP ORF capability	Optional
	Configuring the maximum number of MBGP routes for load balancing	Optional
Configuring a large scale MBGP network	Configuring ipv4 MBGP peer groups	Optional
	Configuring MBGP community	Optional
	Configuring an MBGP route reflector	Optional

Configuring MBGP basic functions

Prerequisites

Before you configure MBGP, make sure neighboring nodes can access each other at the network layer.

Configuration procedure

To configure MBGP basic functions:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Specify a peer or peer group and its AS number.	peer { group-name \| ip-address } as-number as-number	Not specified by default.
4. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
5. Enable a peer or peer group created in IPv4 unicast view.	peer { group-name \| ip-address } enable	Not enabled by default.
6. Specify a preferred value for routes from an IPv4 MBGP peer or peer group.	peer { group-name \| ip-address } preferred-value value	Optional. The default preferred value is 0.

Controlling route advertisement and reception

Configuration prerequisites

You need to configure MBGP basic functions before configuring this task.

Configuring MBGP route redistribution

MBGP can advertise routing information in the local AS to neighboring ASs. It redistributes such routing information from IGP into its routing table rather than learns the information by itself.

To configure MBGP route redistribution:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure MBGP route redistribution.	· Enable route redistribution from another routing protocol: import-route protocol [ { process-id \| all-processes } [ allow-direct \| med med-value \| route-policy route-policy-name ] * ] · Inject a network into the MBGP routing table: network ip-address [ mask \| mask-length ] [ short-cut \| route-policy route-policy-name ]	Use at least one approach. By default, no route redistribution is configured. The allow-direct keyword is available only when the specified routing protocol is OSPF.

NOTE:

· The Origin attribute of routes redistributed into the MBGP routing table with the import-route command is Incomplete.

· The Origin attribute of routes injected into the MBGP routing table with the network command is IGP.

· The networks to be injected must exist in the local IP routing table, and using a routing policy makes route control more flexible.

Configure default route redistribution into MBGP

Using the import-route command cannot redistribute any default route into MBGP. This task allows you to do so.

To configure MBGP to redistribute a default route from another protocol:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter MBGP address family view.	ipv4-family multicast	N/A
4. Enable route redistribution from another routing protocol.	import-route protocol [ { process-id \| all-processes } [ allow-direct \| med med-value \| route-policy route-policy-name ] * ]	By default, no route redistribution is configured. The allow-direct keyword is available only when the specified routing protocol is OSPF.
5. Enable default route redistribution into the MBGP routing table.	default-route imported	Not enabled by default.

Configuring MBGP route summarization

To reduce the routing table size on medium and large MBGP networks, you need to configure route summarization on peers. MBGP supports automatic and manual summarization modes.

· Automatic summarization—Summarizes subnets redistributed from IGP. With the feature configured, MBGP advertises only summary natural networks rather than subnets. The default routes and routes injected with the network command are not summarized.

· Manual summarization—Summarizes MBGP local routes. A manual summary route has a higher priority than an automatic one.

To configure MBGP route summarization:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure MBGP route summarization.	· Enable automatic route summarization: summary automatic · Configure manual route summarization: aggregate ip-address { mask \| mask-length } [ as-set \| attribute-policy route-policy-name \| detail-suppressed \| origin-policy route-policy-name \| suppress-policy route-policy-name ] *	Use either approach. By default, no route summarization is configured. If both are configured, the manual route summarization takes effect.

Advertising a default route to an IPv4 MBGP peer or peer group

To advertise a default route to an MBGP peer or peer group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Advertise a default route to an MBGP peer or peer group.	peer { group-name \| ip-address } default-route-advertise [ route-policy route-policy-name ]	Not advertised by default

NOTE:

With the peer default-route-advertise command executed, the router sends a default route with the next hop being itself to the specified MBGP peer or peer group, whether the default route is available or not in the routing table.

Configuring outbound MBGP route filtering

If several filtering policies are configured, they are applied in the following sequence:

1. filter-policy export

2. peer filter-policy export

3. peer as-path-acl export

4. peer ip-prefix export

5. peer route-policy export

Only the routes that have passed all the configured policies can be advertised.

To configure BGP route distribution filtering policies:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure BGP route distribution filtering policies.	· Configure the filtering of redistributed routes: filter-policy { acl-number \| ip-prefix ip-prefix-name } export [ direct \| isis process-id \| ospf process-id \| rip process-id \| static ] · Apply a routing policy to advertisements to an IPv4 MBGP peer/peer group: peer { group-name \| peer-address } route-policy route-policy-name export · Reference an ACL to filter advertisements to an IPv4 MBGP peer/peer group: peer { group-name \| ip-address } filter-policy acl-number export · Reference an AS path ACL to filter route advertisements to an IPv4 MBGP peer/peer group: peer { group-name \| ip-address } as-path-acl as-path-acl-number export · Reference an IP prefix list to filter route advertisements to an IPv4 MBGP peer/peer group: peer { group-name \| ip-address } ip-prefix ip-prefix-name export	Use at least one approach. By default, no outbound route filtering is configured.

Configuring inbound MBGP route filtering

By configuring MBGP route reception filtering policies, you can filter out unqualified routes from an MBGP peer or peer group.

If several filtering policies are configured, they are applied in the following sequence:

1. filter-policy import

2. peer filter-policy import

3. peer as-path-acl import

4. peer ip-prefix import

5. peer route-policy import

Only the routes that have passed all the configured policies can be advertised.

To configure MBGP route reception filtering policies:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure MBGP route reception filtering policies.	· Filter incoming routes using an ACL or IP prefix list: filter-policy { acl-number \| ip-prefix ip-prefix-name } import · Reference a routing policy to routes from an IPv4 MBGP peer/peer group: peer { group-name \| ip-address } route-policy policy-name import · Reference an ACL to filter routing information from an IPv4 MBGP peer/peer group: peer { group-name \| ip-address } filter-policy acl-number import · Reference an AS path ACL to filter routing information from an IPv4 MBGP peer/peer group: peer { group-name \| ip-address } as-path-acl as-path-acl-number import · Reference an IP prefix list to filter routing information from an IPv4 MBGP peer/peer group: peer { group-name \| ip-address } ip-prefix ip-prefix-name import	Use at least one approach. By default, no inbound route filtering is configured.
5. Specify the maximum number of routes that can be received from an IPv4 MBGP peer/peer group.	peer { group-name \| ip-address } route-limit limit [ percentage ]	Optional. The number is unlimited by default.

NOTE:

Members of a peer group can have different route reception filtering policies from the peer group.

Configuring MBGP route dampening

By configuring MBGP route dampening, you can suppress unstable routes from being added to the MBGP routing table or being advertised to MBGP peers.

To configure BGP route dampening:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure BGP route dampening parameters.	dampening [ half-life-reachable half-life-unreachable reuse suppress ceiling \| route-policy route-policy-name ] *	Not configured by default

Configuring MBGP route attributes

You can modify MBGP route attributes to affect route selection.

Configuration prerequisites

Before you configure this task, you need to configure MBGP basic functions.

Configuring MBGP route preferences

You can reference a routing policy to set preferences for routes matching it. Routes not matching it use the default preferences.

To configure MBGP route preferences:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure preferences for external, internal, local MBGP routes.	preference { external-preference internal-preference local-preference \| route-policy route-policy-name }	Optional. The default preferences of multicast MBGP EBGP, MBGP IBGP, and local MBGP routes are 255, 255, and 130 respectively.

Configuring the default local preference

To configure the default local preference:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure the default local preference.	default local-preference value	Optional 100 by default

Configuring the MED attribute

When other conditions of routes to a destination are identical, the route with the smallest MED is selected.

To configure the MED attribute:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure the MED attribute.	· Configure the default MED value: default med med-value · Enable the comparison of the MED of routes from different ASs: compare-different-as-med · Enable the comparison of the MED of routes from each AS: bestroute compare-med · Enable the comparison of the MED of routes from confederation peers: bestroute med-confederation	Optional. The default MED value is 0. By default, the comparison of the MED of routes is not enabled.

Configuring the next hop attribute

You can use the peer next-hop-local command to specify the local router as the next hop of routes sent to a MBGP IBGP peer or peer group. If load balancing is configured, the router specifies itself as the next hop of route advertisements to the multicast IBGP peer or peer group regardless of whether the peer next-hop-local command is configured.

In a “third party next hop” network, that is, when the local router has two multicast EBGP peers in a broadcast network, the router does not specify itself as the next hop of routing information sent to the EBGP peers unless the peer next-hop-local command is configured.

To specify the router as the next hop of routes sent to a peer/peer group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Specify the router as the next hop of routes sent to a peer/peer group.	peer { group-name \| ip-address } next-hop-local	Optional. By default, the next hop of routes sent to a MBGP EBGP peer/peer group is the advertising router, but that of routes sent to a MBGP IBGP peer/peer group is not.

Configuring the AS-PATH attribute

In general, MBGP checks whether the AS_PATH attribute of a route from a peer contains the local AS number. If yes, it discards the route to avoid routing loops.

To configure the AS-PATH attribute:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure the AS_PATH attribute.	· Specify the maximum number of times the local AS number can appear in routes from the peer/peer group: peer { group-name \| ip-address } allow-as-loop [ number ] · Disable BGP from considering the AS_PATH during best route selection: bestroute as-path-neglect · Configure updates to a peer/peer group to not keep private AS numbers: peer { group-name \| ip-address } public-as-only	Optional. By default: · The local AS number cannot appear in routes from a peer/peer group. · BGP considers AS_PATH during best route selection. · BGP updates carry private AS numbers.

Tuning and optimizing MBGP networks

This task involves resetting MBGP connections and configuring load balancing.

Configuration prerequisites

You must configure BGP basic functions before configuring this task.

Configuring MBGP soft reset

After modifying a route selection policy, you have to reset MBGP connections to make it take effect.

The current MBGP implementation supports the route-refresh feature that enables dynamic route refresh without terminating MBGP connections.

However, if a peer not supporting route-refresh exists in the network, you need to configure the peer keep-all-routes command to save all routes from the peer. When the routing policy is changed, the system will update the MBGP routing table and apply the new policy.

Soft reset through route-refresh

If the peer is enabled with route-refresh, when the MBGP route selection policy is modified on a router, the router advertises a route-refresh message to its MBGP peers, which resend their routing information to the router after receiving the message. Therefore, the local router can perform dynamic route update and apply the new policy without terminating MBGP connections.

To configure MBGP soft reset through route-refresh:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enable BGP route refresh for a peer/peer group.	peer { group-name \| ip-address } capability-advertise route-refresh	Optional Enabled by default

Perform a manual soft reset

If the peer does not support route-refresh, you can use the peer keep-all-routes command to save all the route updates from the peer, and then use the refresh bgp ipv4 multicast command to soft-reset MBGP connections to refresh the MBGP routing table and apply the new policy without terminating MBGP connections.

To configure MBGP manual soft reset

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Disable BGP route-refresh and multi-protocol extensions for a peer/peer group.	peer { group-name \| ip-address } capability-advertise conventional	Optional Enabled by default
4. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
5. Keep all original routes from a peer/peer group regardless of whether they pass the inbound filtering policies.	peer { group-name \| ip-address } keep-all-routes	Not kept by default
6. Return to user view.	return	N/A
7. Soft-reset MBGP connections manually.	refresh bgp ipv4 multicast { all \| ip-address \| group group-name \| external \| internal } { export \| import }	Optional

Enabling the MBGP ORF capability

The MBGP Outbound Router Filter (ORF) feature enables an MBGP speaker to send a set of ORFs to its MBGP peer through route-refresh messages. The peer then applies the ORFs, in addition to its local routing policies (if any), to filter updates to the MBGP speaker, thus reducing the number of exchanged update messages and saving network resources.

After you enable the ORF capability, the local MBGP router negotiates the ORF capability with the MBGP peer through Open messages. That is, the MBGP router determines whether to carry ORF information in messages, and if yes, whether to carry non-standard ORF information in the packets. After completing the negotiation process and establishing the neighboring relationship, the MBGP router and its MBGP peer can exchange ORF information through specific route-refresh messages.

For the parameters configured on both sides for ORF capability negotiation, see Table 1.

To enable the MBGP ORF capability:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enable BGP route refresh for a peer/peer group.	peer { group-name \| ip-address } capability-advertise route-refresh	Optional. Enabled by default. If this feature is not enabled, you need to configure this command. For more information about the command, see Layer 3—IP Routing Command Reference.
4. Enable the non-standard BGP ORF capability for a BGP peer/peer group.	peer { group-name \| ipv6-address } capability-advertise orf non-standard	Optional. By default, standard BGP ORF capability defined in RFC 5291 and RFC 5292 is supported. If this feature is not enabled, you need to configure this command. For more information about the command, see Layer 3—IP Routing Command Reference.
5. Enter MBGP address family view.	ipv4-family multicast	N/A
6. Enable the ORF IP prefix negotiation capability for an MBGP peer/peer group.	peer { group-name \| ip-address } capability-advertise orf ip-prefix { both \| receive \| send }	Optional. Not enabled by default.

Table 1 Description of the both, send, and receive parameters and the negotiation result

Local parameter	Peer parameter	Negotiation result
send	· receive · both	The ORF sending capability is enabled locally and the ORF receiving capability is enabled on the peer.
receive	· send · both	The ORF receiving capability is enabled locally and the ORF sending capability is enabled on the peer.
both	both	Both the ORF sending and receiving capabilities are enabled locally and on the peer, respectively.

Configuring the maximum number of MBGP routes for load balancing

To configure the number of MBGP routes for load balancing:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure the maximum number of MBGP routes for load balancing.	balance number	Not configured by default

Configuring a large scale MBGP network

Prerequisites

Before you configure this task, you need to make peering nodes accessible to each other at the network layer.

Configuring ipv4 MBGP peer groups

In a large-scale network, configuration and maintenance become difficult due to large numbers of MBGP peers. You can configure peer groups to make management easier and improve route distribution efficiency.

To configure an IPv4 MBGP peer group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Create a BGP peer group.	group group-name [ external \| internal ]	Not created by default.
4. Add a peer into the peer group.	peer ip-address group group-name [ as-number as-number ]	By default, no peer is added.
5. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
6. Enable the IPv4 unicast peer group.	peer group-name enable	N/A
7. Add an IPv4 MBGP peer to the peer group.	peer ip-address group group-name	Not configured by default.

CAUTION:

· To configure an MBGP peer group, you must enable the corresponding IPv4 BGP unicast peer group in IPv4 MBGP address family view.

· Before adding an MBGP peer to an MBGP peer group, you must add the corresponding IPv4 unicast peer to the IPv4 BGP peer group.

Configuring MBGP community

The community attribute can be advertised between MBGP peers in different ASs. Routers in the same community share the same policy.

You can reference a routing policy to modify the community attribute for routes sent to a peer. In addition, you can define extended community attributes as needed.

To configure MBGP community:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Advertise the community attribute to an MBGP peer/peer group.	· Advertise the community attribute to an MBGP peer/peer group: peer { group-name \| ip-address } advertise-community · Advertise the extended community attribute to an MBGP peer/peer group: peer { group-name \| .ip-address } advertise-ext-community	Not configured by default
5. Apply a routing policy to routes advertised to an MBGP peer/peer group.	peer { group-name \| ip-address } route-policy route-policy-name export	Not configured by default

CAUTION:

· When you configure MBGP community, you must reference a routing policy to define the specific community attributes, and apply the routing policy for route advertisement.

· For routing policy configuration, see Layer 3—IP Routing Configuration Guide.

Configuring an MBGP route reflector

To guarantee the connectivity between multicast IBGP peers in an AS, you need to make them fully meshed. But this becomes unpractical when large numbers of multicast IBGP peers exist. Configuring route reflectors can solve this problem.

To configure an MBGP route reflector:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter BGP view.	bgp as-number	N/A
3. Enter IPv4 MBGP address family view.	ipv4-family multicast	N/A
4. Configure the router as a route reflector and specify an MBGP peer/peer group as its client.	peer { group-name \| peer-address } reflect-client	Not configured by default.
5. Enable route reflection between clients.	reflect between-clients	Optional. Enabled by default.
6. Configure the cluster ID of the route reflector.	reflector cluster-id cluster-id	Optional. By default, a route reflector uses its router ID as the cluster ID.

CAUTION:

· In general, it is not required that clients of a route reflector be fully meshed. The route reflector forwards routing information between clients. If clients are fully meshed, you can disable route reflection between clients to reduce routing costs.

· In general, a cluster has only one route reflector, and the router ID of the route reflector identifies the cluster. You can configure multiple route reflectors to improve network stability. In this case, you need to specify the same cluster ID for these route reflectors to avoid routing loops.

Displaying and maintaining MBGP

Displaying MBGP

Task	Command	Remarks
Display the IPv4 MBGP routing table.	display ip multicast routing-table [ verbose] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display the IPv4 MBGP routing information matching the specified destination IP address.	display ip multicast routing-table ip-address [ mask-length \| mask ] [ longer-match ] [ verbose ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP peer group information.	display bgp multicast group [ group-name ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display the advertised networks.	display bgp multicast network [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display AS path information.	display bgp multicast paths [ as-regular-expression \| \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP peer/peer group information.	display bgp multicast peer [ [ ip-address ] verbose ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display the prefix entries in the ORF information from the specified BGP peer.	display bgp multicast peer ip-address received ip-prefix [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP routing information.	display bgp multicast routing-table [ ip-address [ { mask \| mask-length } [ longer-prefixes ] ] ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP routing information matching the AS path ACL.	display bgp multicast routing-table as-path-acl as-path-acl-number [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP CIDR routing information.	display bgp multicast routing-table cidr [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP routing information matching the specified BGP community.	display bgp multicast routing-table community[ aa:nn&<1-13> ] [ no-advertise \| no-export \| no-export-subconfed ] * [ whole-match ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP routing information matching an MBGP community list.	display bgp multicast routing-table community-list { { basic-community-list-number \| comm-list-name } [ whole-match ] \| adv-community-list-number }&<1-16> [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP dampened routing information.	display bgp multicast routing-table dampened [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP dampening parameter information.	display bgp multicast routing-table dampening parameter [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display MBGP routing information originating from different ASs.	display bgp multicast routing-table different-origin-as [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display IPv4 MBGP routing flap statistics.	display bgp multicast routing-table flap-info [ regular-expression as-regular-expression \| [ as-path-acl as-path-acl-number \| ip-address [ { mask \| mask-length } [ longer-match ] ] ] [ \| { begin \| exclude \| include } regular-expression ] ]	Available in any view
Display IPv4 MBGP routing information sent to or received from an MBGP peer.	display bgp multicast routing-table peer ip-address { advertised-routes \| received-routes } [ network-address [ mask \| mask-length ] \| statistic ] [ \| { begin \| exclude \| include } regular-expression ]	Available in any view
Display IPv4 MBGP routing information matching an AS regular expression.	display bgp multicast routing-table regular-expression as-regular-expression	Available in any view
Display IPv4 MBGP routing statistics.	display bgp multicast routing-table statistic [ \| { begin \| exclude \| include } regular-expression ]	Available in any view

Resetting MBGP connections

Task	Command	Remarks
Reset specified MBGP connections.	reset bgp ipv4 multicast { all \| as-number \| ip-address \| group group-name \| external \| internal }	Available in user view

Clearing MBGP information

Task	Command	Remarks
Clear dampened routing information and release suppressed routes.	reset bgp ipv4 multicast dampening [ ip-address [ mask \| mask-length ] ]	Available in user view
Clear MBGP route flap statistics.	reset bgp ipv4 multicast flap-info [ regexp as-path-regexp \| as-path-acl as-path-acl-number \| ip-address [ mask \| mask-length ] ]	Available in user view

MBGP configuration example

Network requirements

As shown in Figure 1:

PIM-SM 1 is in AS 100 and PIM-SM 2 is in AS 200. OSPF is the IGP in the two ASs, and MBGP runs between the two ASs to exchange multicast route information. The multicast source belongs to PIM-SM 1, and the receiver belongs to PIM-SM 2. Configure the respective Loopback 0 of Router A and Router B as the C-BSR and C-RP of the respective PIM-SM domains.

Set up an MSDP peer relationship between Router A and Router B through MBGP.

Figure 1 Network diagram

Device	Interface	IP address	Device	Interface	IP address
Source	N/A	10.110.1.100/24	Router C	GE3/1/1	10.110.2.1/24
Router A	GE3/1/1	10.110.1.1/24		S4/1/9/1:1	192.168.4.1/24
	POS5/1/1	192.168.1.1/24		S4/1/9/1:2	192.168.2.2/24
	Loop0	1.1.1.1/32		Loop0	3.3.3.3/32
Router B	POS5/1/1	192.168.1.2/24	Router D	S4/1/9/1:1	192.168.3.2/24
	S4/1/9/1:1	192.168.2.1/24		S4/1/9/1:2	192.168.4.2/24
	S4/1/9/1:2	192.168.3.1/24		Loop0	4.4.4.4/32
	Loop0	2.2.2.2/32

Configuration procedure

1. Configure IP addresses for router interfaces as shown in Figure 1. (Details not shown)

2. Configure OSPF. (Details not shown)

3. Enable IP multicast routing, PIM-SM and IGMP, and configure a PIM-SM domain border:

# Enable IP multicast routing on Router A, and enable PIM-SM on each interface.

<RouterA> system-view

[RouterA] multicast routing-enable

[RouterA] interface GigabitEthernet 3/1/1

[RouterA-GigabitEthernet3/1/1] pim sm

[RouterA-GigabitEthernet3/1/1] quit

[RouterA] interface pos 5/1/1

[RouterA-Pos5/1/1] pim sm

[RouterA-Pos5/1/1] quit

The configuration on Router B and Router D is similar to the configuration on Router A.

# Enable IP multicast routing on Router C, enable PIM-SM on each interface, and enable IGMP on the host-side interface GigabitEthernet 3/1/1.

<RouterC> system-view

[RouterC] multicast routing-enable

[RouterC] interface serial 4/1/9/1:1

[RouterC-Serial4/1/9/1:1] pim sm

[RouterC-Serial4/1/9/1:1] quit

[RouterC] interface serial 4/1/9/1:2

[RouterC-Serial4/1/9/1:2] pim sm

[RouterC-Serial4/1/9/1:2] quit

[RouterC] interface GigabitEthernet 3/1/1

[RouterC-GigabitEthernet3/1/1] pim sm

[RouterC-GigabitEthernet3/1/1] igmp enable

[RouterC-GigabitEthernet3/1/1] quit

# Configure a PIM domain border on Router A.

[RouterA] interface pos 5/1/1

[RouterA-Pos5/1/1] pim bsr-boundary

[RouterA-Pos5/1/1] quit

# Configure a PIM domain border on Router B.

[RouterB] interface pos 5/1/1

[RouterB-Pos5/1/1] pim bsr-boundary

[RouterB-Pos5/1/1] quit

4. Configure C-BSRs and C-RPs:

# Configure the C-BSR and C-RP on Router A.

[RouterA] interface loopback 0

[RouterA-LoopBack0] ip address 1.1.1.1 32

[RouterA-LoopBack0] pim sm

[RouterA-LoopBack0] quit

[RouterA] pim

[RouterA-pim] c-bsr loopback 0

[RouterA-pim] c-rp loopback 0

[RouterA-pim] quit

# Configure the C-BSR and C-RP on Router B.

[RouterB] interface loopback 0

[RouterB-LoopBack0] ip address 2.2.2.2 32

[RouterB-LoopBack0] pim sm

[RouterB-LoopBack0] quit

[RouterB] pim

[RouterB-pim] c-bsr loopback 0

[RouterB-pim] c-rp loopback 0

[RouterB-pim] quit

5. Configure BGP, specify the MBGP peer and enable direct route redistribution:

# On Router A, configure the MBGP peer and enable direct route redistribution.

[RouterA] bgp 100

[RouterA-bgp] router-id 1.1.1.1

[RouterA-bgp] peer 192.168.1.2 as-number 200

[RouterA-bgp] import-route direct

[RouterA-bgp] ipv4-family multicast

[RouterA-bgp-af-mul] peer 192.168.1.2 enable

[RouterA-bgp-af-mul] import-route direct

[RouterA-bgp-af-mul] quit

[RouterA-bgp] quit

# On Router B, configure the MBGP peer and enable route redistribution from OSPF.

[RouterB] bgp 200

[RouterB-bgp] router-id 2.2.2.2

[RouterB-bgp] peer 192.168.1.1 as-number 100

[RouterB-bgp] import-route ospf 1

[RouterB-bgp] ipv4-family multicast

[RouterB-bgp-af-mul] peer 192.168.1.1 enable

[RouterB-bgp-af-mul] import-route ospf 1

[RouterB-bgp-af-mul] quit

[RouterB-bgp] quit

6. Configure MSDP peer:

# Specify the MSDP peer on Router A.

[RouterA] msdp

[RouterA-msdp] peer 192.168.1.2 connect-interface pos 5/1/1

[RouterA-msdp] quit

# Specify the MSDP peer on Router B.

[RouterB] msdp

[RouterB-msdp] peer 192.168.1.1 connect-interface pos 5/1/1

[RouterB-msdp] quit

7. Verify the configuration:

You can use the display bgp multicast peer command to display MBGP peers on each router. For example,

# Display MBGP peers on Router B.

[RouterB] display bgp multicast peer

BGP local router ID : 2.2.2.2

Local AS number : 200

Total number of peers : 1 Peers in established state : 1

Peer AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State

192.168.1.1 100 56 56 0 0 00:40:54 Established

You can use the display msdp brief command to display MSDP peers on a router. For example,

Display brief information about MSDP peers on Router B.

[RouterB] display msdp brief

MSDP Peer Brief Information of VPN-Instance: public net

Configured Up Listen Connect Shutdown Down

1 1 0 0 0 0

Peer's Address State Up/Down time AS SA Count Reset Count

192.168.1.1 Up 00:07:17 100 1 0

07-IP Multicast Configuration Guide

Configuring MBGP

Protocols and standards

Configuration procedure

Advertising a default route to an IPv4 MBGP peer or peer group

Soft reset through route-refresh

Perform a manual soft reset

Enabling the MBGP ORF capability

Configuring the maximum number of MBGP routes for load balancing

Network requirements

Configuration procedure

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