We have done several physical stacks and as @PhilipDAth said, as long as you power them up first on their own before physically stacking them, you will be okay. We have followed the following process: Create the stack in the dashboard by adding the serial numbers Plug in switches on their own with internet access and leave for a few hours Power off switches Install one of the switches in destination and power up, connect devices if needed, to free up space in panel if replacing other switches etc. Install second switch in destination and connect stacking cable(s), then power up Add third etc. if required. As long as you aren't using layer 3 features (we aren't), then it all works fine and there are no connectivity issues for clients, switch reboots etc. We did this with 10.x firmware but haven't added any more yet since moving to 11.x
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