What's causing CRC errors on serial interfaces in multilink T1 group

gwhuang5398 · ‎08-26-2008

I have a 2xT1 running multilink PPP. When I "show interface serial xxx" for the two serial interfaces, both are showing increamenting CRC errors. What can be the cause of it?

Thanks a lot

JORGE RODRIGUEZ · ‎08-26-2008

There could be number of reasons.

Have a look here , go over the check list.

http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00800a758d.shtml

You may also want to check the output of controllers

e.i

show controllers t1

look for line code violation, path code violations, if any clear counters , clearing counters will clear serial counters as well but will give you sort of a start base line , if line code violations or path violation I would recommend to contact your circuit provider to check on the circuit, this could be contributor of crc. Go over the link above for other reasons.

HTH

Jorge

Jorge Rodriguez

Rupesh Kashyap · ‎08-26-2008

Hi ,

This is due to two problems

1. Your Duplex & Speed of physical interface is mis-matching

2. There is physical Cable problem

gwhuang5398 · ‎08-27-2008

I found maybe the clock source on the interfaces are not configured right. Right now both end of the T1 are "clock source local". I'll try changing one end to "line"

Thanks a lot