Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.100.0 - Page 526

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 (domainremote). 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 Example of the show ip msdp sa-cache Command R3#show ip msdp sa-cache MSDP Source-Active Cache - 1 entries GroupAddr SourceAddr RPAddr LearnedFrom 239.0.0.1 10.11.4.2 192.168.0.1 192.168.0.1 Expire UpTime 76 00:10:44 Limiting the Source-Active Cache Set the upper limit of the number of active sources that the Dell Networking OS caches. The default active source limit is 500K messages. When the total number of active sources reaches the specified limit, subsequent active sources are dropped even if they pass the reverse path forwarding (RPF) and policy check. To limit the number of sources that SA cache stores, use the following command. • Limit the number of sources that can be stored in the SA cache. EXEC Privilege mode show ip msdp sa-limit If the total number of active sources is already larger than the limit when limiting is applied, the sources that are already in Dell Networking OS are not discarded. To enforce the limit in such a situation, use the clear ip msdp sa-cache command to clear all existing entries. 526 Multicast Source Discovery Protocol (MSDP)