I have seen this problem before. Basically you have a layer 1 problem thus, your fiber.
Some possible problems to look at: 1. Is your fiber longer than IEEE standard? With GBIC-SX, 550m for multi-mode With GBIC-LH, 300m for multi-mode With GBIC-LH with modal cable, 550m for multi-mode With GBIC-LH, 5K for single mode My guess is you are using MM with SX GBICs and you have patch panels in the middle of you run and you are also using fiber patch cords. Look for loose or bad ends, dust lint between your patches, and/or even a bad run. Hope this helps. Jim P.S. Sei in Italia? Di dove? ----- Original Message ----- From: "Luca Ciasca" To: Sent: Thursday, February 13, 2003 4:37 AM Subject: flapping of trunk ports (trunk non-trunk) [7:62951] > Hi all, > > Is there anyone who have suggestion for this problem: > > in my catalyst 6500 I have a lot of message like this, even 60 for day: > > Switch_1> (enable) 04/21/1998,03:15:40:DTP-5:Port 1/1 has become non-trunk > > Switch_1> (enable) 04/21/1998,03:15:41:DTP-5:Port 1/1 has become trunk > > I specify that: > > 1) both of the ends of this link are in "trunk on" mode (no auto, no > desirable) > 2) The fiber seems OK, indeed I have actived the UDLD in aggressive mode for > this link and the stase is still: "bidirectional" > 3) both of the ends of this link have "dot1q" encapsulation > > I have read that a valid workaroud is to migrate from the "on" mode to > "nonegotiate" mode, but I don't want that this just hide the problem, > without solving it. > > Any suggestion? > > Thanks > > Luca [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=63021&t=62951 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
