Header Only - DO NOT REMOVE - Extreme Networks

Replace a complete switch stack

Hey guys, it looks like we are having an issue with a stack that has 5 nodes. At some point or another a node will fail so it came to be that all nodes will be replaced in this stack. My question is that since I have a limited time frame of 2 hours, would it be best to do 1 node at a time starting from 5 and work my way up to 1 (Master) or do I set up the new stack and copy config files? More than likely the new switch's will have newer image than what we currently have. I've swapped out nodes before but have never been faced with a situation like this.

Any ideas?

9 replies

Userlevel 1
I david, i would ensure that the switches have the same image and setup the stack all in once.
I think this is a mostly a matter of preference.

That said I would stack all the new switches copy the configuration over and then just replace the whole stack. Just make sure you identify and label any cables that need to go back into ports with none standard configurations.

Depending on how bad your cabling is you should be able to swap the whole stack this way in an hour.
Userlevel 2
I just went through the same thing. I built the new stack with new firmware and configured them how the existing stack is (vlans etc..). I didn't want to put the existing config on the new stack for fear of any issues with it. I then removed the old switches, installed the new switches and have been great since. I would not recommend replacing nodes one at a time, sounds like a nightmare in the making!
Userlevel 4
I agree with everyone else - start clean and carefully swap cables to the new stack. Not sure of your overall architecture, but if this stack is in any way providing redundant server or uplink connections, you may want to also consider a design using MLAG, splitting the stack and allowing for you to take half offline without affecting the other. Won't help today, but might save you some time in the future when doing normal maintenance.
I appreciate the info, I'd like to take advantage of using newer image over what we have now which is 16. It's a bit of a pita with how much configuration there is but I guess in the long run we'd be better off. So it looks like the game plan is this:

1-Verify/identify what vlans are on ports and uplinks of existing stack and label cables to specific vlans
2-Set up new stack at my desk mimicking existing stack. If I use the same IP I won't be able to connect to network, so I guess I can keep it offline.
3-Shut down existing stack, pop in new stack, plug cables and cross fingers.

Sound about right?
Sounds about right.

If your not changing the config, you should be able to simply save it as a script pull it off and run the script on the new stack. Watch your password encryption if changing code versions.

sho config | include untagged

Usualy works pretty well for identifying non-standard ports. Not sure about your environment but we find most of our customers have 90% of there ports configured on one VLAN and just a handful scattered between things like APs and cameras. Typicly you can just label that last 10% of ports and not worry about where the other go.

Only other thing to watch is ports that have their speed hard set for older devices.
Userlevel 7
This may not be helpful for you now, but I wanted to mention it for those replacing standalone switches (and stacks in certain scenarios), who find this thread in the future.
There's a "cloning" tool in EXOS now:
@drewc. Awesome, now I know moving forward!

Thanks again guys!
Userlevel 5
Drew actually beat me to it. I was going to suggest a combination of cloning to create a USB. Then USBZTP on the new stack master. Then run clone.py slot all to sync all of the slots on the new stack to the master. Available in EXOS 22.2.

I do have a version of cloning, soon to be out, that will clone an entire stack from USB or across a network and is compatible with 22.2 and later.

FWIW, I've posted the clone.py doc to our EXOS applications github under an experimental directory, until the clone.py app download is available.