Posted by: Sulaiman Syed
CCIE, Cisco, how, monitor, reliable, RIP, route, router, static, to, track
Adding reliable default route with RIP
The command for distributing a default route into RIP process is very straight forward. Lets go with the syntax straight away.
default-information originate route-map RELIABLE
route-map RELIABLE permit 10
match ip address prefix-list DUMMY_TRACKED
set interface Serial 1/0
ip prefix-list DUMMY_TRACKED seq 5 permit 10.10.10.10/32
ip route 10.10.10.10 255.255.255.255 null0 track 1
Here we have added a route map to the default-information command. This route map will match an ip address. This IP address is the Route. That means, IF that route (10.10.10.10) is in the routing table, then distribute the default route. This can be used with real routes, or as in our case with dummy route. Second is command “set” is telling the router on which interface advertise the default route.
So we have created a dummy route, and tracking it with IP SLA. The interesting twist here, is that the SLA is for real interface.
ip sla 1
icmp-echo 22.214.171.124. source-interface s1/1
ip sla schedual 1 start now life forever
track 1 ip sla 1
So, if the real route goes down, the dummy route will be out. Once that happened, the default-information command will cease to work.