I have a Cisco 3845 that has sync and async circuits connected via serial ports.
When we attempted to cutover to the new routers from the older 2600's we were using, the sync circuits came online without a problem. The async circuits, however, did not. The only change on the configurations of the new routers is that 'ENCAPSULATION SLIP' is enabled for the async circuits.
We feel fairly certain that this is the cause of our problems. We tried disabling encapsulation on each interface, which is not working. We type 'NO ENCAPSULATION SLIP' and then we go back to look at the configs for that interface, and it is still there.
Does anyone know why it is doing this? If so, how can we fix this problem?