With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
natConfigGroup
nat Config Group
1.3.6.1.2.1.123.2.1.1
A collection of configuration-related information required to support management of devices supporting NAT.
Back to NAT-MIB MIB page.
IPHost Network monitor allows you to monitor natConfigGroup 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.