I have two core routers, one has a T3 connected to it the other an OC3. The T3 connects to my core 2 switch and the OC3 connects to my core 1 switch. It is all EIGRP for the routing protocol. The T3 is strictly for backup I am not doing any load balancing. My issue is that some times the T3 router advertises routes that sometimes screw up a couple of my branch sites. By that I mean the branch site will not be able to get to a particular destination on the WAN. What usually fixes the problem is me clearing the routing table on the T3 router and then all is right with the world again. Obviously I don't want to have to keep doing this. What I want is for the T3 router to be in a total backup capacity. If the OC3 goes down the routing protocol recognizes there is another way out via the T3 and advertises that. I tried to play around with some of the metrics on the T3 router but that doesn't seem to help. Any thoughts?