C9200 Replacing switch in stack behavior

[P675]

 all,

I want to have a spare switch ready to swap a failed switch in a stack. I have it configured as a standalone switch just in case a single switch also fails and I need to swap it quickly. People without switch access may need to perform this also.

What I need to check is how a spare switch will join a stack and will the port configuration be synced. Let's say we have this situation:

• 2 switch stack, Switch 1 Pri 15, Switch 2 Pri 10
• Swap switch is set to default Switch 1 Priority 1
• Switch 1 in the stack fails, switch 2 becomes active
• I disconnect switch 1, put the swap switch in it's place, connect stacking cables and power it up
• Is the newly added switch going to become switch 1, and have all switch 1's port configuration?
• If it's switch 2 that fails, and replaced, will the swap switch be automatically renumbered to switch 2 and take switch 2's port configuration?

It would simplify things a lot if the cables into the switch can go back in the same numbered ports, but if the newly added switch retains it's port configuration, that makes changing out the switch take a lot longer. Or if the new switch gets numbered 3 and all the ports start with 3/0/x, then there is more configuration to do. I just want to make it easy for non-network IT staff to change a switch if I'm not there.

Thanks for any suggestions!

[Jens Albrecht]

Hi @P675,

basically replacing a faulty stack member is really as easy as mounting and cabling a new device no matter which stack member has failed. So the short answer to both of your questions is YES.

There are a few things to keep in mind:

• The IOS-XE software version must match

• The license level must match

• The operational mode (Install / Bundle) must match
  Note: If you use Install mode the auto-upgrade feature can be used to resolve such issues
  Use the command "software auto-upgrade enable" to activate this feature

• The new switch must not be member of another stack and must be added while powered

• Make sure to monitor the log messages via Console/SSH to observe any issues during boot-up of the new member

Since you only have 2 members in both cases the old remaining switch stays/becomes active and the newly added switch will be standby after successfully joining the stack. Hence the config will then be synced to the new switch as well.

No matter which switch fails the active takes care of assigning the correct switch number to the new member so you do not need to worry about the port configuration.

So the process is really as simple as power-down the faulty device, swap it with a new one, connect all cables and power it up provided that the above mentioned conditions are met.

HTH!