With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cldFailoverUnitType
cld Failover Unit Type
1.3.6.1.4.1.9.9.99.1.3.3
The failover unit type, which is determined by Failover serial cable; primary or secondary.
Back to CISCO-LOCAL-DIRECTOR-MIB----B MIB page.
IPHost Network monitor allows you to monitor cldFailoverUnitType 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.
