With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cggsnGeoPassiveStdbyIfName
Cisco Gateway GPRS Support Node Geo Passive Stdby If Name
1.3.6.1.4.1.9.9.724.1.1.2
This variable specfies name of the passive interface configured
Back to CISCO-GGSN-GEO-MIB MIB page.
IPHost Network monitor allows you to monitor cggsnGeoPassiveStdbyIfName on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.