With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cisMcastGroupPortList
Cisco IGMP Snooping Mcast Group Port List
1.3.6.1.4.1.9.9.263.1.7.1.1.8
This object indicates the set of ports on which IGMP Membership Reports are received for the group indicating interest to receive traffic sent to the group.
Back to CISCO-IGMP-SNOOPING-MIB MIB page.
IPHost Network monitor allows you to monitor cisMcastGroupPortList on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.