I have 2 identical Cisco 2690x with flex stack plus modules installed in both. I have provisioned the first and it is up and running. When I add the second to the flex stack module and turn it on, it powers up and the flex stack indicator is green, but it doesn't seem to create the stack. In the CNA, the secondary switch is not even showing in the list.

Everything is brand new. Switches, cables, and stack modules. What am I missing?enter image description here

Master Config

  • Please edit your question to include the configurations of both the switch and the switch that you are trying to add to the stack.
    – Ron Maupin
    Commented Aug 15, 2017 at 22:10
  • It's tough without more info but if you are using the 10 gig cable disconnect them and run this in global config mode if you haven't already. switch stack port-speed 10. I have no idea if that's your issue but people forget that command. Config manual cisco.com/c/en/us/td/docs/switches/lan/catalyst2960xr/hardware/…
    – Fixitrod
    Commented Aug 15, 2017 at 22:49
  • Sorry, that was quick start. Here's the config manual cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/…
    – Fixitrod
    Commented Aug 15, 2017 at 22:50
  • @Fixitrod I'm using the 20 gig cable. It's a flex stack plus module Commented Aug 15, 2017 at 23:13
  • Can you post configs as Ron has mentioned? Is the second switch defaulted? I've had better luck doing a write erase on the switch I'm adding and making sure firmware is the same on both. I know it's supposed to take care of that even with stackwise it's not as automatic as it's supposed to be. But, we will need configs to help you further. Or, use that configuration manual to troubleshoot.
    – Fixitrod
    Commented Aug 15, 2017 at 23:25

1 Answer 1


You need to:

Remove the current configuration; in config mode for both switches, remove the provisioning config, on master:

no switch 2 provision ws-c2960x-48lps-l

Power off the switches. Remove and reseat the stack modules. Power up and reboot the switches with no stack cables connected. After reboot has finished, set the priority of the switch you want master:

switch 1 priority 15 

Now connect stack cables port 1 master to port 2 slave and port 1 slave to port 2 master. Slave will now reboot and the stack is formed.

  • 1
    Also, make sure both switches are running the same OS version. It is required to form a stack.
    – John K.
    Commented Aug 16, 2017 at 13:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.