With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cbdSIIndex
CISCO BRIDGE DOMAIN SI Index
1.3.6.1.4.1.9.9.642.1.2.1.1.1
This object indicates an arbitary index that uniquely identifies the Service Instance to which this bridge domain member belongs to.
Back to CISCO-BRIDGE-DOMAIN-MIB MIB page.
IPHost Network monitor allows you to monitor cbdSIIndex 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.