Configuring MSDP Globally

To configure Multicast Source Discovery Protocol (MSDP), you must enable MSDP and configure the MSDP peers.
Note: The PIM Sparse Rendezvous Point (RP) can also be an MSDP peer.

It is strongly recommended that you use the connect-source loopback command when configuring the MSDP peers. If you do not use the connect-source loopback command, the device uses the IP address of the outgoing interface. You should also make sure the IP address of the connect-source loopback is the source IP address used by the PIM RP and the BGP device. Devices that run MSDP usually also run BGP.

  1. Enter global configuration mode. 
    device# configure terminal
  2. Enter loopback interface configuration mode. 
    device(config)# interface loopback 1
    The loopback interface is used as the source interface for sessions with the peer.
  3. Enter the IP address to be used as the source address for peer sessions. 
    device(config-lbif-1)# ip address 10.9.9.9/32
  4. Exit to global configuration mode. 
    device(config-lbif-1)# exit
  5. Enable MSDP. 
    device(config)# router msdp
  6. During editorial review, it was asked why step 6 and 8 are both used when they are similar commands. Are both needed? Can I get help understanding the difference?
    Configure MSDP peers.
    During editorial review, it was brought up that in our documentation we should use an internal IP address or use addresses that are reserved for documentation and are not assigned to anyone. What is an address that could be used in this and other examples?
    device(config-msdp-router)# msdp-peer 205.216.162.1 connect-source loopback 1
    By default, the device uses the subnet address configured on the physical interface where you configure the neighbor as the source address for sessions with the neighbor.
    Added new step below for 10.0.20a.
  7. Limit the source active messages for MSDP peers.

    The peer IP must be configured to set the source active message limit.

    By default the device uses 4096 as the source active message limit for peers.

    device(config-msdp-router)# sa-limit in 205.216.162.1 3000
  8. Configure an MSDP peer, specifying the loopback interface and the pre-configured TCP authentication keychain name to be used for sessions with the peer.
    Note: It is not advisable to change the underlying configuration of the TCP AO keychain specified in the MSDP peer configuration or to remove or replace the keychain. Any of these changes may cause the existing MSDP or BGP sessions to flap.
    device(config-msdp-router)# msdp-peer 205.216.162.1 connect-source loopback 1 ao chain1
  9. Clear the MSDP peer session for the keychain configuration to take effect.
    How do you clear the MSDP peer session?
added the sa-limit to this example. Verify that this is the correct order. I cannot verify this CLI on the setup that I have access to.

The following example configures a loopback interface, enables MSDP, and configures a neighbor as an MSDP peer using the loopback interface as the source interface and address. 

device# configure terminal
device(config)# interface loopback 1
device(config-lbif-1)# ip address 10.9.9.9/32
device(config-lbif-1)# exit
device(config)# router msdp
device(config-msdp-router)# msdp-peer 205.216.162.1 connect-source loopback 1
device(config-msdp-router)# sa-limit in 205.216.162.1 3000
device(config-msdp-router)# msdp-peer 205.216.162.1 connect-source loopback 1 ao chain1
Parent topic: Configuring Multicast Source Discovery Protocol