Actually the link provided doesn't actually satisfies my question .
What more i learned was that backup router only works when there are 2 routing engines Why is it so ??
Secondly the backup router should be the out of band IP of the directly connected router for that you need a static route towards the fxp of your directly connected router.
Thirdly backup router is just configured to genrate trap not to forward traffic to backup router is it true. Fourth documentaton confuses me Duh . It some time feels as that you configure backup to access the management of the router whose RPD restarts. Can you please clear these points.
The purpose of the backup-router statement is not to forward transit/pfe traffic. This is for local management of the router, via the out of band interface (fxp0). It allows the router to install a default or static route to a destination, before the routing protocol process (rpd) is up and running. My answers to your questions are below.
My questions are
1- Is there any specific risk when u install a default route in the forwarding table eventhough it is removed from the
forwarding table once the RPD of router A restarts
2-what should be the backup router IP The IP address of the interface directley connected to router A or loopback
3- What if i install router A as backup for router B and router B backup for router A
Thanks & Regards
A1. There shouldn't be any risks assoicated with doing this. Just make sure the backup router address specified is reachable and directly connected. When RPD starts, the backup route is removed. And, any default static, or protocol learned route will be installed. In the case of a backup routing-engine (usually RE1), the backup router remains active, unless Nonstop Routing is configured.
A2. The backup router address should be an address that is directly connected to fxp0.
A3. This can work if the fxp0 of each router is connected to aninterface on the other router, that provides the reachability you need.
This is probably a good time to point out that traffic is not forwarded between pfe and fxp0 interfaces.