CSCwb50229 - C9300-NM-2Y Link Down When Connected to IE Switches

[leccles]

Ran into this bug as well. We were running 17.06.03. One side of the link (3850) said it was connected and lit up, the other side on the 9300 was not connected - down/down and no link light. No cdp neigh. I upgraded to 17.10.01 and after it applied the new iOS and rebooted the trunk link immediatly came up. Sh cdp showed the neighbor. Since 17.10.01 is the latest, I am leary of other bugs. We will upgrade slowly. 

[Leo Laohoo · Accepted solution]

Try using 17.9.2.

[leccles]

Thanks, but already upgraded it to 17.10.1 and it is working. I just wanted to post the fix for others who are pulling out their hair from this issue. 

[Leo Laohoo]

I understand and agree the issue is resolved in 17.10.1, however, 17.10.1 is a single-release version only.  

[leccles]

That is a good point. The newest version is what the Cisco TAC suggested. I will try 17.9.2 on another switch and search online for known bugs for it.  Thanks.  

[Leo Laohoo]

Do let us know if 17.9.2 works or not. 

PS:  17.9.3 is meant to be coming out in the next two weeks.

[leccles]

I installed17.9.2 on the 9300 (same switch) and it did work with the 2y network module. I tried looking around on Cisco site and on Google for any possible bugs with 17.9.2 and unable to find this addressed. Do you know where to look online to see what bugs, if any, are associated with 17.9.2? Thanks.

[Leo Laohoo]

Look under the Caveat section.

[leccles]

This is a great resource! Thanks for taking the time to respond!