The primary connections to our remote routers are point-to-point frame relay circuits. We have ISDN connections that will act as a backup, in case the primary fails.
My question is, what is the best backup method when there is no dynamic routing between the routers?
I would like to use the backup interface command, but I dont think that will work with static routing.
The floating static routes is a possibility, but it has its pros and cons that I dont like. I was hoping to use the backup interface utility, but I do not think that is possible with static routing.
I agree with most of what Victor says here. I would like to clarify one point: you commented and Victor sort of agreed that it would work only if there were a dynamic routing protocol. This is not a correct assumption. It can also work quite well when there are only static routes. The key concept is the floating static route has an administrative distance higher than the default of 1. With its administrative distance configured the floating static route works fine with dynamic routing protocols and with static routes also. Whatever the primary route is (whether from dynamic or from static) its administrative distance is lower than the floating static and is placed into the routing table. When the primary route fails and is withdrawn from the routing table then the floating static is placed into the routing table. This would allow it to send traffic over your ISDN connection.