With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cd11IfVlanEncryptKeyIndex
Cisco DOT11 Interfaces Vlan Encrypt Key Index
1.3.6.1.4.1.9.9.272.1.1.1.9.1.2
This object is a representative of the corresponding 802.11 WEP Key Index used when transmitting or receiving frames with this key. SNMP table indexing conventions require table index to be non-zero. Therefore, this object has to be one greater than the actual 802.11 WEP key index. A value of '1' for this object corresponds to a value of '0' for the 802.11 WEP key index.
Back to CISCO-DOT11-IF-MIB MIB page.
IPHost Network monitor allows you to monitor cd11IfVlanEncryptKeyIndex 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.