Creating switch stack with existing switches in production

[Terence Lockette]

All,

I can't seem to find a Cisco doc explaining this question so I thought I'd post it here.  I have a 24 port 2960-X and three 48 port GE 2960 switches that I would like to stack together.  My question is, do I need to wipe the switches that will not be stack masters before adding them to the stack?  Or is there a way to add them to the stack without wiping the config?  I assume that if I don't have to wipe the config, then a reboot will wipe mostly everything with the exception of the port configs.  Please advise, thanks!

Regards,

Terence

[Leo Laohoo · Accepted solution]

My question is, do I need to wipe the switches that will not be stack masters before adding them to the stack?

The recommended way is YES.  Wipe the config of the new members.  You want to know why?  

IF you don't wipe the config from the new members and then you stack them, there is a chance that the entire stack might reboot (if the stacking was done incorrectly).  If the new stack members have config, they just might take over from the original stack master. 

Have I stacked new members without wiping config?  Yes I have, several times (particularly when I forget to bring my laptop and/or console cable).   But I will always recommend to wipe the config.  

[Terence Lockette]

Leo,

I think I'll follow the recommendation and wipe the config from the other stack members.  This will be done after hours so reboots won't matter just as long as I get it back up before everyone gets in the next day.

Regards,

Terence

[Leo Laohoo]

Thanks for taking the time to rate our posts, Terence.  :)

Here's a very, very useful "tip" which a lot of people don't read the manual about:  POWER DOWN the new stack members before connecting the stacking cable to the existing switch stack.  

If new stack members have power and you connect the stacking cables to the existing switch stack, the entire stack will reboot.  If you power down the new stack members and connect the to the existing switch stack, the new switch stack members will join the existing stack seamlessly.

[Terence Lockette]

Leo,

Thanks for the tip!  I'll likely take care of this within the month or so and will let you know how it worked out for me.  Thanks again!

[Leo Laohoo]

Keep us posted with the update, Terence.  :)