With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
pimRPSetGroupAddress
pim RP Set Group Address
1.3.6.1.3.61.1.1.6.1.1
The IP multicast group address which, when combined with pimRPSetGroupMask, gives the group prefix for which this entry contains information about the Candidate-RP.
Back to PIM-MIB MIB page.
IPHost Network monitor allows you to monitor pimRPSetGroupAddress on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.