Configuring BGP A-D Multicast VPN

The configuration of BGP A-D multicast VPN enables the Auto Discovery (AD) of PEs on the same VPN and allows multicast VPN services to run in public network tunnels based on PIM-SSM distribution trees.

Usage Scenario

Before the BGP A-D MVPN is introduced, MD MVPNs can establish only PIM-SM MDTs. This is because PEs belonging to the same VPN cannot detect each other's peer information. As a result, PEs belonging to the same VPN cannot detect the multicast source, and therefore are unable to send PIM-SSM Join messages to the multicast source to establish a PIM-SSM MDT.

After the BGP A-D MVPN is introduced, MD MVPNs can also establish PIM-SSM MDTs. On a BGP A-D MVPN, PEs obtain and record peer information about a VPN by exchanging BGP Update packets that carry A-D route information. Then, these PEs send PIM-SSM Join messages directly to the multicast source to establish a PIM-SSM MDT. After the PIM-SSM MDT is established, the BGP A-D MVPN transmits multicast services over a public network tunnel based on the PIM-SSM MDT.

If multicast VPN is implemented in BGP A-D mode, the configured A-D mode must be consistent with the A-D address family type configured in the BGP view.

Pre-configuration Tasks

Before configuring BGP A-D Multicast VPN, configure an MD VPN.

Procedure

Run system-view
The system view is displayed.
Run bgp as-number
The BGP view is displayed.
Run ipv4-family mdt
The BGP-MDT address family view is displayed.
Run peer { group-name | ipv4-address } enable
Route exchange with a specific peer or peer group is enabled in the BGP-MDT address family view.
Run quit
Return to the BGP-MDT address family view.
Run quit
Return to the BGP view.
Run ip vpn-instance vpn-instance-name
The VPN instance view is displayed.
Run ipv4-family
The VPN instance IPv4 address family is enabled and its view is displayed.
Run auto-discovery mdt [ import route-policy route-policy-name ]
The MDT-SAFI A-D mode is configured for the VPN instance IPv4 address family.
Run commit
The configuration is committed.

Verifying the Configuration

After the BGP A-D multicast VPN is configured, run the following commands to check the configurations:

Run the display pim [ vpn-instance vpn-instance-name | all-instance ] routing-table [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } | outgoing-interface { include | exclude | match } { interface-type interface-number | vpn-instance vpn-instance-name | register | none } | mode { ssm | sm } | flags flag-value | fsm ] ^* [ outgoing-interface-number [ number ] ] command to check the PIM routing table.
Run the display multicast [ vpn-instance vpn-instance-name | all-instance ] routing-table [ group-address [ mask { group-mask | group-mask-length } ] | source-address [ mask { source-mask | source-mask-length } ] | incoming-interface { interface-type interface-number | register | mcast-extranet } | outgoing-interface { include | exclude | match } { interface-type interface-number | vpn-instance vpn-instance-name | register | none } ] ^* [ outgoing-interface-number [ number ] ] command to check the multicast routing table.
Run the display multicast-domain vpn-instance vpn-instance-name share-group [ local | remote ] command to check the Share-Group information of a specified VPN instance in a multicast domain.