Hello,

After you install and configure a new link between your switches, you need to add new routing entries to your routing table with a higher administrative distance so that they will become active only if the existing primary connection fails.

On site A, these two lines will be added:

ip route 10.32.50.0 255.255.255.0 X.X.X.X 2

ip route 10.32.52.0 255.255.255.0 X.X.X.X 2

On site B, this line will be added:

ip route 0.0.0.0.0 0.0.0.0 Y.Y.Y.Y 2

where X.X.X.X and Y.Y.Y.Y are addresses of the new interfaces that interconnect your routers. The number 2 at the end of each command is the administrative distance of the route. Normal static routes have administrative distance of 1 which means they are preferred. The administrative distance of these routes has been deliberatly increased to make them less preferred.

For these scenarios, it is also recommended that you define your static routes using both the IP address and the output interface in one command to make sure that the routing entry will be guaranteedly removed from the routing table if the outgoing interface fails, so for example:

ip route 10.32.50.0 255.255.255.0 Fa3/4 X.X.X.X 2

ip route 10.32.52.0 255.255.255.0 Fa3/4 X.X.X.X 2

Best regards,

Peter