We are installing a network based on 20 Cisco3550 switches, connected to a Cisco4507 with redundant Fibre optique on trunking mode, and we see that a lot of ports became err-disabled state, and some time even the trunk links can take this state.
That sure if the cables are out of specifications can cause that on the access ports, but with the fibre optique link we dont understand why, even if we tested the entire fibre optique links and all its OK.
Can some one help me or have a url link that explain that?
reason for the errdisable port status can vary from duplex and speed mismatches to UDLD problems on fiber ports. Do you see any error counters going up on those ports that go into errdisable ? Can you post the configuration of one of the 'problem' switches ?
Will you please post the output from "sh int status err-disabled" command taken on affected switch, which will provide additional clue. Out of the 7 possible reasons I have mostly experienced link-flaps and loopbacks with Cat3550.
Thanks & Regards,