With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cnatAddrMapStatsEntry
cnat Address Map Stats Entry
1.3.6.1.4.1.9.10.77.1.3.2.1
An entry (conceptual row) containing NAT statistics per address map.
Back to CISCO-IETF-NAT-MIB MIB page.
IPHost Network monitor allows you to monitor cnatAddrMapStatsEntry 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.