Ensure existing IOS is not downgraded when new stack member is added

[Frank Hansen]

In a switch stack consisting of two 2960x switches, a third 2960x needs to be added having lower IOS version than existing (not to replace stack master).

Existing stack members are running 15.2 and new member is running 15.0.

How do I ensure, that existing stack members are not downgraded to added third stack member IOS (is it always the stack master that dictates which IOS version to be used, also even if command "boot system switch all flash:/[IOS patch]" has been issued)?

Switch priority has been set on the two existing stack members with priorities 15 and 10. No provisioning has been set for new stack member as of yet (does this have any influence in regards to existing IOS compared to new stack member IOS version or is it only used for pre-configuring switch ID and priority in stack along with port configuration?).

boot auto-copy-sw is enabled on stack.

New stack member should be completely wiped for configuration (startup-config erase and vlan.dat erased) (it's located remotely, so can't access it).

Br

Frank

[Ben Walters · Accepted solution]

The software version for the switches in the stack is determined by the master, since you set your other switches with a higher priority you shouldn't have to worry about the new switch becoming master.

More info can be found here under the Auto-Upgrade section

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/stack_manager/configuration_guide/b_stck_152ex_2960-x_cg/b_stck_152ex_2960-x_cg_chapter_010.html

[Frank Hansen]

Thank you for your response Ben. I will then plan on the adding of the new switch.

Br

Frank