Monitoring Reliable Static Routing

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Reliable static routes silently appear or disappear from the IP routing table based on the state of the attached track object; the only way to monitor their state is to use the show ip route track-table command.

Show tracked routes
GW#show ip route track-table
 ip route 0.0.0.0 0.0.0.0 Serial0/0/0 10 name ISP_A track 100 state is [down]

However, state tracking generates logging messages, and you can use the debug track command to get even more details.

Track state logging and debugging
GW#debug track
06:49:44: Track: 100 Down change delayed for 10 secs
06:49:54: Track: 100 Change #24 ip sla 100, reachability Up->Down
06:49:54: %TRACK-6-STATE: 100 ip sla 100 reachability Up -> Down
06:50:24: Track: 100 Up change delayed for 20 secs
06:50:34: Track: 100 Up change delay cancelled
06:58:59: Track: 100 Up change delayed for 20 secs
06:59:19: Track: 100 Change #25 ip sla 100, reachability Down -> Up
06:59:19: %TRACK-6-STATE: 100 ip sla 100 reachability Down -> Up
The debugging printout illustrates a real-life scenario where the next-hop router became temporarily reachable during the bootstrap process and disappeared a few seconds later (the change delay cancelled printout).

Suppose you need more than the logging messages the track objects generate. In that case, you can use the Embedded Event Manager with the event track configuration command to trigger EEM applets (or TCL scripts) whenever a track object’s state changes.

For example, we’ll define two EEM applets: one triggered on the down change, and another triggered on the up change. We’ll use a simple syslog msg action; you can add other actions, like emailing the network manager or even reconfiguring the router (the complete router configuration is available on GitHub).

The following printouts show a sample EEM configuration and the printouts it generates.

IOS EEM applet generates syslog messages on tracked object state change
event manager applet ISP_A_down
 event track 100 state down
 action 1.0 syslog msg "ping to 172.16.1.2 from GigabitEthernet 0/2 failed"
event manager applet ISP_A_up
 event track 100 state up
 action 1.0 syslog msg "172.16.1.2 is reachable"
Sample track logging and EEM printouts
00:38:52: %TRACK-6-STATE: 100 ip sla 100 reachability Up -> Down
00:38:52: %HA_EM-6-LOG: ISP_A_down: ping to 172.16.1.2 from GigabitEthernet 0/2 failed
00:39:22: %TRACK-6-STATE: 100 ip sla 100 reachability Down -> Up
00:39:22: %HA_EM-6-LOG: ISP_A_up: 172.16.1.2 is reachable

Revision History

2025-03-31
  • Recreated the router configurations and printouts with IOSv release 15.6(1)T.
  • Object tracking generates logging messages in newer IOS releases

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