With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cisRxLeaves
Cisco IGMP Snooping Rx Leaves
1.3.6.1.4.1.9.9.263.1.2.1.1.8
Total IGMP Leave messages that have been received at an interface.
Back to CISCO-IGMP-SNOOPING-MIB MIB page.
IPHost Network monitor allows you to monitor cisRxLeaves on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.