3750 Stackwise Flapping ?!?

joshhunter · ‎11-23-2010

Just recently we have had 3-4 switches from the same customer all with the Stackwise flapping problem.

*Mar 1 00:03:23.826: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:03:25.839: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:03:28.859: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:03:29.866: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:03:35.905: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:03:38.925: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:03:39.932: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:03:41.945: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:03:44.965: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:03:47.985: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:03:48.992: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:03:49.998: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:03:56.038: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:03:58.051: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:03:59.058: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:04:02.078: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:04:03.085: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:04:04.091: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:04:05.098: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:04:06.104: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:04:07.111: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:04:09.124: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:04:13.151: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

*Mar 1 00:04:17.177: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state DOWN

*Mar 1 00:04:20.197: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP

Any ideas ? they are all switches from 2004.

Tried different IOS and different stack cables and still same issue.

andtoth · ‎11-23-2010

Hi,

Did you have a chance to review the Troubleshooting Switch Stacks documentation?

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

Refer to the "Problem: StackWise Port is Flapping" section.

Best regards,

Andras

joshhunter · ‎11-23-2010

Forget what I said about 2004 switch one is also flapping and is 2008.

These conditions might cause StackWise port flapping:

•An unreliable or intermittent (bad) connection between a StackWise cable connector and the switch stack port connector

Tried different cable and screwed tight

•A defective StackWise cable

Tried an old and new StackWise cable and works fine with other switches

•A defective StackWise interface on a switch

Possible but detects stack cables and seems to be only being caused on Stack1. But all 3 interfaces are broken?

andtoth · ‎11-23-2010

Hi,

Could you please give the IOS versions where you're observing this issue and the Part Number and Serial Number of the switches as well?

Are you observing flapping on only one stack?

How many stack links are affected by the flapping?

How many switches are there in the stack?

Did you try power cycling the whole stack where the flapping happens?

If you swap 2 stack cables in the stack, does the flapping stay between the same ports or does it follow the stack cable?

Andras