Trunking problems with GIG

paul.merritt · ‎01-04-2005

We are running a Gig uplink between two buildings using Cisco Cataylst 5500 series swiches on both ends, WS-X5403 GIG modules on both ends. I have been noticing in the syslog that the trunk port for this uplink flaps between dot1q and non trunk for about 7-10 seconds periodically. Has anyone had similar problems?

Prashanth Krishnappa · ‎01-04-2005

Do all the 3 ports flap at the same time? We had few bugs which were closed

http://www.cisco.com/cgi-bin/bugtool/onebug.pl?bugid=CSCdv65200

http://www.cisco.com/cgi-bin/bugtool/onebug.pl?bugid=CSCea16149

Check for obvious things such as bad GBICs, fiber. If replacing fiber/GBIC does not help, I suggest that you open a TAC case to get investigated further

paul.merritt · ‎01-05-2005

we only have one port of the three hooked up right now.

I have checked all the bug reports an havent seen anything related to the sotware release running on the switch (5.5 (20))

glen.grant · ‎01-04-2005

Are you seeing any incrementing errors on the uplinks ? If you do a show counters mod/port are you seeing incrementing errors . We have not seen any problems with 5500's and gig unless there is a fiber or gbic problem . Usually you will see incrementing counters if it is a physical layer problem .

paul.merritt · ‎01-05-2005

I am not seeing any FCS errors, runts/giants, or any type of broadcast or allignment errors.

glen.grant · ‎01-05-2005

the only other thing you could check is to make sure whatever patch cable you are using matches what is being used between the buildings , if it's multimode then use multimode patches . Also make sure the spanning tree timers match on both ends and one end didn't get changed to a different setting . We have 5.5.20 running gig without a problem . Have you checked the light levels coming out of each end to see if they are within specs for the gbic recievers ???

paul.merritt · ‎01-05-2005

I set the flowcontrol to match on both sides... im going to see if that helps

bmutcherson · ‎01-05-2005

verify that the encapsulation is the same on both switches either both dot1q or ISL.and that both are in trunk mode.