Multicast Source Discovery Protocol | 629
Prevent MSDP from Advertising a Local Source
In Figure 28-14, R1 stops advertising source 10.11.4.2. Since it is already in the SA cache of R3, the entry 
remains there until it expires.
Figure 28-14.  Preventing MSDP from Advertising a Local Source
Display the configured SA filters for a peer using the command show ip msdp peer from EXEC Privilege 
mode (see Figure 28-14).
Task Command Syntax Command Mode
Prevent an RP from advertising a source in the SA 
cache.
ip msdp sa-filter list in peer list ext-acl
CONFIGURATION
[Router 1]
R1_E600(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_E600(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_E600(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
R3_E600(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_E600(conf)#do show ip msdp sa-cache
R3_E600(conf)#