Users Guide

Enable MSDP
Enable MSDP by peering RPs in different administrative domains.
1 Enable MSDP.
CONFIGURATION mode
ip multicast-msdp
2 Peer PIM systems in different administrative domains.
CONFIGURATION mode
ip msdp peer connect-source
Example of Configuring and Viewing MSDP
R3(conf)#ip multicast-msdp
R3(conf)#ip msdp peer 192.168.0.1 connect-source Loopback 0
R3(conf)#do show ip msdp summary
Peer Addr Local Addr State Source SA Up/Down
Description
To view details about a peer, use the show ip msdp peer command in EXEC privilege mode.
Multicast sources in remote domains are stored on the RP in the source-active cache (SA cache). The system does not create
entries in the multicast routing table until there is a local receiver for the corresponding multicast group.
R3#show ip msdp peer
Peer Addr: 192.168.0.1
Local Addr: 192.168.0.3(639) Connect Source: Lo 0
State: Established Up/Down Time: 00:15:20
Timers: KeepAlive 30 sec, Hold time 75 sec
SourceActive packet count (in/out): 8/0
SAs learned from this peer: 1
SA Filtering:
Input (S,G) filter: none
Output (S,G) filter: none
Manage the Source-Active Cache
Each SA-originating RP caches the sources inside its domain (domain-local), and the sources which it has learned from its
peers (domain-remote).
By caching sources:
• domain-local receivers experience a lower join latency
• RPs can transmit SA messages periodically to prevent SA storms
• only sources that are in the cache are advertised in the SA to prevent transmitting multiple copies of the same source
information
Viewing the Source-Active Cache
To view the source-active cache, use the following command.
• View the SA cache.
EXEC Privilege mode
show ip msdp sa-cache
Multicast Source Discovery Protocol (MSDP) 571