Catalyst 9300 OS stacking question

[kyle311]

OK, stupid question.  I have a client with an isolated environment. They have two single catalyst 9300's and are looking to add a new switch to each, making two stacks.  Since i do not have access to the equipment, I asked for show vers on both the current and new switches.  The new switches are running a newer OS. 

Their plan is to have the new switches be the secondary, attacheing each to one of the currents.after changing the numbering and priority. 

Question is, what would happen when they are connected, since the new switches are running a new version of OS & will be set with a lower stack priority?

[Reza Sharifi]

Usually, it is not recommended to have 2 different versions of software on 2 different switches in a stack. The entire stack should have the same version. Also, check the part numbers to make sure there is compatibility between the new hardware and the old one before stacking them.

HTH

[Dustin Anderson]

by default if you do a show stack, you will see the second switch listed with a version mismatch.

I believe you can issue the command 'install autoupgrade' and it will upgrade/downgrade the mismatched version to the master's code version. I did this once a while ago, so you may need to tab out the command if it's more than just that.

And on a note on switch numbers, it should be defaulted to 1, and if it comes online and sees it exist, it will enumerate down until it finds a number missing, so it should change to switch 2 automatically.

[Leo Laohoo]

Make sure the following command (below) is in the configuration: 

software auto-upgrade enable

When adding the new switch members to the stack, the new switches are POWERED OFF.  Do not connect the stacking cables if the new switches have power.  Connecting the power-stack cable is the very, very, very last step.  

Connect the stacking cables and then energize the new switch members.