With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
mnCOA
mn COA
1.3.6.1.2.1.44.1.3.2.1.1.2
A care-of address being offered by this foreign agent or a co-located care-of address which the mobile node has associated with one of its own network interfaces.
Back to MIP-MIB MIB page.
IPHost Network monitor allows you to monitor mnCOA on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.