This article describes the issue of the MSDP Originator ID using the Router ID, when showing the msdp source-active group, instead of the RP address.
The Router ID is being shown as the msdp source-active group originator; instead of the RP address. Consider the following configuration:
# show routing-options { router-id 10.255.14.30 pim { rp { local { address 192.168.195.46; lo0 { unit 0 { family inet { address 10.255.14.30/32; address 192.168.195.46/32; and this output: > show msdp source-active Group address Source address Peer address Originator Flags 230.0.0.0 192.168.195.46 local 10.255.14.30 Accept
# show routing-options { router-id 10.255.14.30 pim { rp { local { address 192.168.195.46; lo0 { unit 0 { family inet { address 10.255.14.30/32; address 192.168.195.46/32;
> show msdp source-active Group address Source address Peer address Originator Flags 230.0.0.0 192.168.195.46 local 10.255.14.30 Accept
The IP address of the source-active originator uses the configured router-ID or the lo0 interface, if the router-ID is not configured. This is by design, so that remote routers can know what router is the active router.
The RP address can be shared between multiple routers in any cast fashion; so if the RP address was the originator, then it could cause confusion, as the RP address does not truly identify the active RP. Using the lo0 interface or router ID allows the source to be identified, as the router-ID and lo0 interface should be configured as individual IP addresses.