With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cmiNtRegNAI
Cisco Mobile IP Nt Registration NAI
1.3.6.1.4.1.9.9.174.1.6.9
The identifier associated with the mobile node.
Back to CISCO-MOBILE-IP-MIB MIB page.
IPHost Network monitor allows you to monitor cmiNtRegNAI 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.