The follow is a snippet of config from an example router I have access to;
ip sla monitor 1
type echo protocol ipIcmpEcho 220.127.116.11 source-interface Dialer1
ip sla monitor schedule 1 life forever start-time now
track 1 rtr 1 reachability
delay down 20 up 20
track 21 interface Dialer1 ip routing
ip route 0.0.0.0 0.0.0.0 Dialer1 220 track 21
As far as I can tell, the goal here is to use object tracking of the IP SLA Monitor (track object 1) to track the results of the ICMP echo test, and provide a backup static route, shoud the exisitng one be lost because of a link going down (or similar). But the static route depends on tracked object 21. Have I missed something, are these somehow linked?
"track 21 interface Dialer1 ip routing", is the "ip routing" state of dialer 1 updated automatically by the track 1/IP SLA object? Or, as I assume, has this router been misconfigured, and track 1 is not actually being used, and it's all hanging on track object 21?
Yes, the static (default) route uses only the track 21 and not the track 1 as you want.
You should modify the configuration as follows in order to use the track object 1 (=> sla 1) instead of track 21 :
ip route 0.0.0.0 0.0.0.0 Dialer1 220 track 1
You can use the next command, sh ip sla monitor statitistics in order to check that the sla operation is successful and the default route is installed to the routing table.
Hope that helps!