Setting up StackWise Power

[jnesbitt1]

I am fairly new to the StackWise technology so this may be an easy question. I have a bunch of cisco stacks currently deployed, all 3750-X models with all their power slots filled; needless to say this is a waste of power and money so I want to enable StackWise Power on these stacks. I have researched this for hours, read all the white pages but I am unable to determine if I am able to connect the StackWise power cable while the switches are on. Is this safe to do and will the switches see the cable or would they need to be reloaded? Thanks in advanced.

[Marvin Rhoads]

jnesbitt,

I'm 99% sure you can - I know I've plugged in (or reseated) the StackWise cables themselves to amend a stack that wasn't properly connected without issue or reload.

The StackPower cable should be even less disruptive as it plays no part in the forwarding or control plane of the switches.

Note that a power stack is limited to fewer (5 IIRC) switches than a data stack (up to 9). You can have a 9 switch data stack that is comprised of two power stacks, if you follow me.

[Randall Nieland]

StackPower is limited to 4 switches, so if you have a full data stack of 9 switches, you can create two distinct StackPower stacks, as Marvin suggests, but you'll have to consider the best option for leaving one switch out of the StackPower configuration.

Cisco does mention that you can technically span a StackPower stack across two data stacks, but this is not a supported configuration.

You can also make changes to the StackPower topology while the switches are running, though I would still consider that to be work done during a maintenance window, as you never know when an odd bug might surface, particularly if you're going to be pulling unnecessary power supplies after the StackPower is implemented.

Randy