3750 stack manager flapping chronic issues

[scottdware]

Hello,

So, we have a few thousand 3750's in our network, and most of them are in a 2-9 switch stack. We often see a lot of these messages:

%STACKMGR-4-STACK_LINK_CHANGE: Stack Port X Switch X has changed to state DOWN

%STACKMGR-4-STACK_LINK_CHANGE: Stack Port X Switch X has changed to state UP

We replace cables, replace switches, reload switches (in the correct order)...but they just seem to be endless. We've had these in our environment for a while now, 2-3 years, some if not more. Cables are not really cramped at all, either.

I just want to try and find a way to cut down on these, as I know that we're going to get them anyway.

We are running the following on our switches:

WS-C3750-48P/WS-C3750-48PS

12.2(25)SEE2 IPBASEK9-M

Thank you in advance!

[Amit Singh]

Scott,

There are a few bugs that I have found describing your behaviour with the IOS version you are running. I am sure you might have looked at this link below for troubleshooting this issue, but just to make sure that you dont have any incompatibility issues.

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/troubleshooting/switch_stacks.html

Also, could you please check the white sticker on the STACK cable and see if there is any number listed with "FOX XXXX".

An IOS upgrade will resolve the issue but lets check the stack cable first.

Cheers,

-amit singh

[scottdware]

Thank you, Amit, for the quick reply.

I checked a few of the stacks here in one of our campus buildings, but all of the stackwise cables start with 72-XXXX.

I'll have to get a few of our techs to get that info from our remote sites. Is there a link or description of the bug that you could provide me to look at. I'm just curious as to what it says.

Thanks!

[Shashank Singh]

Hi Scott,

Stack port flaps may be an indication of hardware fault with the switches. Please go through the following link :

http://tools.cisco.com/Support/BugToolKit/search/getBugDetails.do?method=fetchBugDetails&bugId=CSCsj80738

Though there is no precise bug responsible for the behavior, proactive upgrade of IOS on the switch is a good idea.

Cheers,

Shashank

Please rate if you found the content useful

[Amit Singh]

Hi Scott,

Here are a couple of the bug ID's

CSCsj80738

CSCed30201

Also, could you please confirm the full part number of the cable starting with 72-XXXX-XX.

Do you see anyone of these?  72-2632-01, 72-2633-01 & 72-2634-01 with FOX somewhere on the sticker like FOX1003 etc...

Cheers,

-amit singh

[scottdware]

So, I've checked most of the cables here between our campus buildings, and some of our techs have been telling me what we have at our remote locations...and looks like most of our "shorter" stackwise cables have the part number 72-2632-01, and our "longer" ones have the part number 72-2633-01. I have found a few that have the 72-2634-01, as well.

[Shashank Singh]

Hi Scott,

These cables are substandard and should be replaced. Please open a TAC case and request replacement: For details visit http://tools.cisco.com/Support/BugToolKit/search/getBugDetails.do?method=fetchBugDetails&bugId=CSCed30201

Cheers,

Shashank

P.S. Please rate helpful posts

[scottdware]

Thank you for the info, Shashank! I see that in the bug report, there is mention of the word "FOX" or "F0X" on these cables as well. The thing is, most of the cables that we have do not have "FOX" or "F0X" on them, but the part numbers definitely do match up with these ones:

72-2632-01

72-2633-01

72-2634-01

So does that mean that these cables are still suspect? Thanks!

[Shashank Singh]

Hi Scott,

Yes, they still are. There is an internal field notice which talks about the affected serial numbers and it seems that there is a match.

HTH,

Shashank

Please rate if you found the content useful

[scottdware]

Thanks to everyone on this thread. Were working with our local Cisco engineer on our account to move forward with the replacement parts.

Sent from Cisco Technical Support iPhone App

[Shashank Singh]

Hi Scott,

Glad to hear that you are going for the replacements which should fix the problem. It would be awesome if you could rate the posts that helped you. This would help the new visitors to this thread to identify the correct answers quickly

Cheers,

Shashank

[scottdware]

Sure thing, just took care of it!