With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
csApsSwitchReason
cs Aps Switch Reason
1.3.6.1.4.1.9.9.126.1.2.1.1.15
This object indicates APS line switch reason.
Back to CISCO-SONET-MIB MIB page.
IPHost Network monitor allows you to monitor csApsSwitchReason 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.
