With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cmlrInstAddrConvFailureCounts
Cisco Multi-layer Routing Inst Address Conv Failure Counts
1.3.6.1.4.1.9.9.396.1.1.1.26
Count of message signal units received that could not be routed because GTT address failed to convert. This object counts are also included in the cmlrInstAbortCounts object.
Back to CISCO-ITP-MLR-MIB MIB page.
IPHost Network monitor allows you to monitor cmlrInstAddrConvFailureCounts 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.