With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
natAddrPortBindSessions
nat Addr Port Bind Sessions
1.3.6.1.2.1.123.1.8.1.12
Number of sessions currently using this BIND.
Back to NAT-MIB MIB page.
IPHost Network monitor allows you to monitor natAddrPortBindSessions on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.