With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cnatSessionSecondBindId
cnat Session Second Bind Id
1.3.6.1.4.1.9.10.77.1.2.5.1.15
The natBindId of the 'other' NAT binding incase of Twice NAT. An instance of this object contains a valid value only if the binding type for this session is TwiceNAT.
Back to CISCO-IETF-NAT-MIB MIB page.
IPHost Network monitor allows you to monitor cnatSessionSecondBindId on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.