errdisable cause loopback

pccthailand · ‎04-28-2008

what's the meaning of this error and how can i fix it ?

Thanks

cisco_lad2004 · ‎04-28-2008

look for a physical loop in ur switch.

there must be some miscabling causing a loop.

Try sh cdp neighbor, and u might just see that on a given port ur neighbor is the switch itself.

HTH

Sam

Sushil Kumar Katre · ‎04-28-2008

Sometimes its caused on the interfaces connected to the IP Phones.

If you find that the cable is fine, disable the keepalive on the switch interface.

-> Sushil

wilson_1234_2 · ‎04-28-2008

I have seen this error on fiber trunks between switches, causing the trunk port to shut down.

According to Cisco, it is caused by a keepalive entering the same port it left from.

As mentioned earlier, removing the keepalive will solve the problem, and is the default (no keepalive) on later OS revisions for the Gigabit ports requiring a GBIC.