With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
msdpSACachePeerLearnedFrom
msdp SA Cache Peer Learned From
1.3.6.1.3.92.1.1.6.1.4
The peer from which this SA Cache entry was last accepted. This address must correspond to the msdpPeerRemoteAddress value for a row in the MSDP Peer Table.
Back to DRAFT-MSDP-MIB MIB page.
IPHost Network monitor allows you to monitor msdpSACachePeerLearnedFrom on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.