With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cseStaticIpxExtRouterTable
CISCO SWITCH ENGINE Static Ipx Ext Router Table
1.3.6.1.4.1.9.9.97.1.2.16
A table of external routers which are enabled for Layer 3 IPX switching by the switching engine. This table may contain routers that have not yet been discovered by the device.
Back to CISCO-SWITCH-ENGINE-MIB MIB page.
IPHost Network monitor allows you to monitor cseStaticIpxExtRouterTable 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.