trying to eliminate a T1 backhaul line with model 1750 units. Have DSU-t1 units and have it configured for GRE tunnel. The 2 FastEthernet0 interfaces talk to each other, and the T1's show that they are working to the model 1750's, but the T1's seem to cycle and not stay on constantly, plus they do not seem to connect to the tunnel. ??
Any help is appreciated ??