Users Guide

Preventing MSDP from Advertising a
Local Source
To prevent MSDP from advertising a local source, use the following command.
• Prevent an RP from advertising a source in the SA cache.
CONFIGURATION mode
ip msdp sa-filter list in peer list ext-acl
Example of Verifying the System is not Advertising Local Sources
In the following example, R1 stops advertising source 10.11.4.2. Because it is already in the SA cache of R3, the
entry remains there until it expires.
[Router 1]
R1(conf)#do show run msdp
!
ip multicast-msdp
ip msdp peer 192.168.0.3 connect-source Loopback 0
ip msdp sa-filter out 192.168.0.3 list mylocalfilter
R1(conf)#do show run acl
!
ip access-list extended mylocalfilter
seq 5 deny ip host 239.0.0.1 host 10.11.4.2
seq 10 deny ip any any
R1(conf)#do show ip msdp sa-cache
MSDP Source-Active Cache - 1 entries
GroupAddr SourceAddr RPAddr LearnedFrom Expire UpTime
239.0.0.1 10.11.4.2 192.168.0.1 local 70 00:27:20
R1(conf)#do show ip msdp sa-cache
MSDP Source-Active Cache - 1 entries
GroupAddr SourceAddr RPAddr LearnedFrom Expire UpTime
239.0.0.1 10.11.4.2 192.168.0.1 192.168.0.1 1 00:10:29
[Router 3]
R3(conf)#do show ip msdp sa-cache
R3(conf)#
To display the configured SA filters for a peer, use the show ip msdp peer command from EXEC Privilege
mode.
Logging Changes in Peership States
To log changes in peership states, use the following command.
• Log peership state changes.
CONFIGURATION mode
ip msdp log-adjacency-changes
Multicast Source Discovery Protocol (MSDP) 691