With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cieIfDot1qCustomEtherTypeEntry
cie If Dot1q Custom Ether Type Entry
1.3.6.1.4.1.9.9.276.1.3.1.1
An entry containing the custom EtherType information for the interface. Only interfaces with custom 802.1q ethertype control are listed in the table.
Back to CISCO-IF-EXTENSION-MIB MIB page.
IPHost Network monitor allows you to monitor cieIfDot1qCustomEtherTypeEntry 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.