I have an existing switch stack with two MS225 and need to add a third switch to the stack. What is the procedure to add a switch to an existing stack?
I looked at one of our networks. Looks like you may have to delete the stack, then create it with the 3 desired switches. Based on my prior experience with stacking, make sure you do it during a maintenance window. It'll likely cause some outage. Also verify your wiring between the 3 switches so they have redundancy. How are you wiring them?
I have the wiring part down, lots of experience with Cisco classic stacking. I was hoping for a way to just add to the stack like you can with Cisco classic switches so i would not have to take the network down or risk it going down.
Plug the new switch into an existing connection, and give it a good 45 minutes to upgrade its software. It must be running the same software as existing stack members.
Hopefully your existing stack has a full "ring".
Break the ring, and plug in your new switch, and re-form the ring.
Within maybe 5 to 10 minutes if you go to "Switch/Switch Stacks". It will report there is an additional member than can be added to the stack. Let it add it to the stack.
You are done. Note that depending on the code version they have be a short disruption to service while you do this, so do it out of peak time.
I think they could stop forwarding packets for 15s. It is a little version dependent. This is not something I have done very often.
My experience has been much different than @PhilipDAth. Stacks seems to always give me trouble.
@cvashel2 keep us posted on how it goes. I'd be interested to know if Philip's more streamlined method works out so I can try using it in the future.
so i called Meraki support and they told me to follow the procedure @PhilipDAth described and suggested that there should be no downtime. i will report back once i have add the switch.
I've found that even on current 10.X firmware versions, if you break the stack ring for any reason while the stack is running, you will need to reboot the stack once the ring is fixed or you'll have issues down the road. At this point I always reboot a stack if anything happens to the stacking ring because of this.
so we added the third switch to the stack. it turns out that there was only one stacking cable installed on the original 2 switches in the stack so we technically did not have to "break" the stack to add the new switch.
we first plugged the new switch in on an access port and allowed it to connect to the portal and any firmware needed. once it had been green in the portal for 15 or 30 min we powered the new switch down and connected the stacking cables to form a ring and powered the new switch on. once it came up and showed on line in the portal we added it to the stack. after that there was about 5 minutes where the switches in the portal went yellow, warning about stacking config being out of sync. no traffic was dropped and all switches turned green in the portal. Meraki has also automatically scheduled a switch upgrade in a few days coincidentally so we will get a reboot for that shortly.
otherwise it looks good.