With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cagwImpactedIp
Cisco's ASN Gateway Impacted Ip
1.3.6.1.4.1.9.9.638.1.5.2
This is the address of the device impacted by the event that caused the generation of the notification containing this object.
Back to CISCO-ASN-GATEWAY-MIB MIB page.
IPHost Network monitor allows you to monitor cagwImpactedIp 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.