With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
caonPepSecurityFailures
Cisco AON Pep Security Failures
1.3.6.1.4.1.9.9.646.1.1.8.1.6
This object indicates the number of times authentication and certificate validation failures were encountered during PEP execution. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of caonCounterDiscontinuityTime object.
Back to CISCO-AON-STATUS-MIB MIB page.
IPHost Network monitor allows you to monitor caonPepSecurityFailures 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.