2600 Router, Line Protocol Down

[mwurm]

I have a number of 2600 series routers configured with 1 Fast E, 1 CSU/DSU and 1 16 port Async card, routing IP. I seem to be having trouble every once in a while the "Line Protocol" will go down on the Serial interface. To fix this I have to go out on site and re-boot the router. This seems to fix the problem for a few months. Is there a cache or buffer that maybe needs to be cleared? Any suggestions would be apprecieated.

[michael-faust]

The only thing that comes to mind right without more information is a loopback. Is it possible that someone is looping back the interface and leaving it looped? If you have 'remote loopback' enabled, try disabling it and see what happens.

If it continues to happen, you need to troubleshoot before you reload. Look at the other end of the serial link. What is the status? Take a looping plug with you. Loop back the CSU. Does this bring it up? Loop the line toward the far end. Did the status change?

I know it's hard to leave it down while you troubleshoot, but if you want to fix it, it must be done.

[mwurm]

Thanks, I will try this the next time it happens.

[james.henderson]

I had a problem similar to yours...One of our serial interfaces was having frame slips and bit errors. After awhile, the bit errors would cause the interface to drop. Once I cleared the interface the interface would go back up for awhile.