With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
pnniRouteAddrTimeStamp
pnni Route Address Time Stamp
1.3.6.1.4.1.353.5.4.1.1.19.4.1.16
Indicates when the connectivity from the advertising node to the reachable address prefix became known to the local node.
Back to PNNI-MIB MIB page.
IPHost Network monitor allows you to monitor pnniRouteAddrTimeStamp 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.