Cisco 3750 Stack Master Issue

[arabindas]

Hi Everybody,

I was evaluating the Cisco 3750 stack feature in a lab. I have configured the priority 15 on the preferred switch to be the master always. I noticed that once the stack master switch goes down, the member switch becomes the master, which is perfectly alright. But when again the previous master is back online, it is the member switch no longer the master. Any way is there, where we can ensure that always the preferred switch to be the master?

Thanks

Arabinda

[Giuseppe Larosa]

Hello Arabinda,

the election procedure is quite conservative

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_example09186a00807811ad.shtml#election

and the priority is the only tool I think.

Some tests can be more meaningful using three switches in the stack.

Hope to help

Giuseppe

[arabindas]

Hi Giuseppe,

Thanks for your reply. But the priority tool is not working. I tried even the prsistent - mac address thing, still that does not helps oo. Unfortunately I have only two C3750 in lab, so cannot introduce a 3rd switch to test.

Thanks

Arabinda

[gnijs]

You want to enable pre-empt on master election ie when a switch with prio 15 boots up, it should FORCE the stack so he becomes master. I do not know of such a method, other than to manually reload the existing master. Besides, why would you want to do this ? This would only introduce another stack interruption. In general, it doesn't matter which switch in a stack is master. If you have a routing stack (enhanced image) i highly recommend using the "mac-persistent" command, so that the stack mac doesn't change with the master switch, but besides this, i don't really see an advantage in pre-empt forcing a master switch.