9300 Stack and Etherchannel

[stuartmacrae]

Hi, I have a 9300 stack and two single 2960x switches. I created a Port channel on each 2960x going to seperate 9300 Stack member for resillency. As all kit is Cisco I used PAGP. It was fine for weeks and then err-disabled. The logs are default 4096k so I didnt manage to see what caused it. I can't see anything wrong with the topology as the 9300 Stack Logically is 1 Switch so I have no idea why this happend. No other Switches coming off the 9300 Stack were affected.

[Joseph W. Doherty]

Hmm, cannot say what the possible cause was, although even though all equipment is Cisco, would recommend using LACP rather than PAGP.

[Javier Acuña]

Thank you for communicating with the Cisco community before lifting the Port-channel. You verified the violation status of the interfaces, this could help you determine the root cause of your failure

Remember to rate this answer, this motivates you to continue collaborating in the cisco community.

[balaji.bandi]

not sure what code running, worth looking below bugs :

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvt59448/?rfs=iqvred

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvg77396/?rfs=iqvred

[stuartmacrae]

OK I've checked and both versions are not listed - shown below

9300 Version 16.9.1r [FC2]

2960x Version 15.2(3r)E1

And all interfaces in bundle are Auto @ Gig

One thing I forgot to mention was the Err-disabled ports were on both single 2960x Switches.

[balaji.bandi]

 Err-disabled ports were on both single 2960x Switches.

what is the cause of err-disabled? is this one time issue, or recurring?  ( how far these switches? any comments room involved with the patch pannels ?)

[stuartmacrae]

Didn't get chance to get logs for the cause of err-diable unfortunatley.

MDF 9300 to IDF 2960x (Both 2960x in same Rack). connectivity from MDF to IDF 15 meter copper

I've checked all Cabling and no issues as I recall seing a large number of Input errors and Giants. 

Both 2960x are currently running on a single cable each on a stander uplink (No Etherchannel config).

[balaji.bandi]

since you did not have logs and what is the reason for err-disable cause,

i am sure Cat 9300 not rebooted, have some logs ?

can you post relavant config or full config of Cat 9300 and C2960 (if the config is notconfidentail)

show switch from Cat 9300

show spann sum (from both)

show run from both the device

[stuartmacrae]

I'm unable to post config.

Sorry

[Javier Acuña]

You indicate that you are working without etherchannel. Have you validated the spanning three? Can you have a path redundancy block?

Remember to rate this and all helpful answers

[stuartmacrae]

Yes at the moment they (each 2960x) are running without etherchannel on a single copper uplink each. This was done to quickly get the devices back up. As they are single links and the 2960x Switches are not linked in any way, Spanning tree is not an issue.

Previosuly they topolgy attached on original post was working. Something happend, I put a quick fix in place. No I have chance to look at the issue and try and get it back up I was after a little input to see if anyone had any ideas or experiecne with anything similar.

[paul driver]

Hello

what makes you think it the 9300 that has a issue - do the logs of the 2960x show anything

Also what was the cause for the error-disable as usually the software would state the root cause?

[stuartmacrae]

I don't have the logs as they Logs were overwritten on all devices. I'm not pointing at any of the devices in particular.

[stuartmacrae]

Last night - I have since torn down the temp single uplinks, increased the log buffers, reset interface counters and activated the Port Channel again.

The topology attached on original post is now active.