Does anyone know what exactly would cause a T1 serial interface (point to point T1) to be up but with line protocol down (looped)? I am not showing any CSU/DSU errors or loopbacks but the interface is showing this loopback. I seached CCO and have seen plenty of references to line protocol being up (looped) but no line protocol down (looped). I have a ticket open with the telco now to see if they are screwing anything up but am not sure they are. Any thoughts? I have also tried a differant CSU/DSU and serial port with the same symptoms.
I have this problem too.