ERS 3600 Stack Replacing a 24 Port with a 48 Port Switch

[UCPNetworkTeam]

Hi I have a switch stack of 5 48 Port 3650GTS and one 24 port 3626 GTS Switches. I am attempting to replace the 3626GTS switch with another 3650GTS switch.

When I swap out the switches currently, the SFP ports light up but the switch is never recognized in the stack. When I put the 24 port switch back in place the stack recognizes it instantly.

I have confirmed that both Firmware and software versions are the same.

I am thinking it may have something to to with  auto-unit-replacement AUD looking for a 24 port switch, and finding a 48. Anyone run into this?

[UCPNetworkTeam · Accepted solution]

Going to try this that was found on another discussion 

Did you enable stacking on the SFP+ ports? By default, they are SFP+ ports and the mode needs to be changed to stacking.

On an ERS 3600, run “stacking-ports mode stacking”

On an ERS 3500, run “rear-ports mode stacking”

Save and reboot each switch after running the command.