With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
addressMapLastChange
address Map Last Change
1.3.6.1.2.1.16.13.5.1.5
The value of sysUpTime at the time this entry was last created or the values of the physical address changed. This can be used to help detect duplicate address problems, in which case this object will be updated frequently.
Back to RMON2-MIB MIB page.
IPHost Network monitor allows you to monitor addressMapLastChange on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.