cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
2776
Views
15
Helpful
15
Replies

Catalyst 9300-24T stack stops forwarding all traffic?

I built a stack of two C9300-24T switches yesterday to replace a pair of Catalyst 3560X's.  Very simple cut-&-paste configuration with some HSRP IPv4 addresses being removed and the HSRP VIP's added as the physical addresses.

About an hour after the swap out of the 3560X's to the C9300's it just stopped working.  Everything connected through the switch at L3 just stopped.

There are two CPE routers connected on a /29 subnet running HSRP - one connected to switch #1 and one connected to switch #2.  HSRP and L2 connectivity between these two CPE routers was working, however they couldn't ping the SVI interface on the C9300.

From a 2960X L2 switch connected on a trunk to this stack I could see CDP information for the C9300, however I couldn't the other way around from the C9300 to the 2960X.  From the L2 2960X I couldn't ping the C9300, from the C9300 I couldn't ping anything.

 

After troubleshooting for an hour from the console and not getting anywhere I just rebooted it and everything came back.  I checked the stacking cables and they were all finger tight so don't think its just a loose stacking cable.  I left if for a couple of hours and everything was OK.

However looking at our monitoring platform this morning at 6:15am it failed again.  I can logon to the CPEs and HSRP is OK between them, they can ping each other but they can't ping the SVI interface on the switch stack.  I suspect a reboot of the C9300 will temporarily will fix this, but it will reoccur.

 

Has anyone seen this behaviour?  Luckily there are no staff on site today.

 

 

15 Replies 15

Thanks for the update. 
I have never seen a behaviour like this from a stacking cable.  

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: