Cisco 3750x – Set Switch Priority in Stack

These are instructions on how to specify a single switch in a switch stack to become the master switch every time and not hope the stack master election picks the one you want through a reboot. To do this we will rig the stack master election by manually setting the switch we want to become the master to the highest priority while we set all the member switches to the lowest priority. The stack priority can range from 1 to 15 and the switch with the highest priority will become the master switch.

First find the priority of all switches in the stack.


From this output we can see that the stack master election is rigged for switch 2 in the stack to become master, I do not want this I want switch 1 to become the master. To accomplish this we will need to set switches 2-4 with a priority of 1


Then set the switch 1 to a priority of 15, anything higher than 1 will work to cause it to be the stack master, but this is easier to distinguish.


Now to confirm issue a ‘show switch’ command to validate that switch 1 has the highest priority, which it does but the stack master will not change unless you reboot. Issue a ‘reload’ command to reboot the stack and trigger another election, which will elect switch 1 as the master


Once all switches in the stack finish booting up issue a ‘show switch’ command again and you will see switch 1 which is designated a priority of 15 has become the master.


Also note if you are watching the boot-up of the switch stack on the console port of one of the switches you can see during the boot-up process what switch was elected master.


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