With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cagwUserGrpRejSession
Cisco's ASN Gateway User Group Rejected Session
1.3.6.1.4.1.9.9.638.1.3.4.1.1.30
The number of session rejected due to service mode not operational.
Back to CISCO-ASN-GATEWAY-MIB MIB page.
IPHost Network monitor allows you to monitor cagwUserGrpRejSession 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.