Stack Switch - Master Switch Change

[aakash-agarwal]

Seen multiple threads but our case is diff - 

We have 3 switches - 1 master 2 members. Master has some issues needs to be replaced. Also, it is a mixed stack like 1 switch 24 port and others 48. The way we did replace of a master switch now:

1) Put matching image in the new switch

2) Stack priority number to 1 new switch

3) Change the priority of the existing master to 1 and reload the stack so another one selected as master 

4) once stack rebooted replace previously known master 

5) once stack is in sync change master back to previous one and reload the stack

Can someone tell if thats right way of doing it? we already did it however i am more concerned about two reboots, i could let the new master be as master and that would save me one reboot but just trying to see options. 

[Reza Sharifi]

Your step will work fine.  You can also shorten the duration and one less reboot by eliminating step-3

so,

1) Put matching image in the new switch

2) Stack priority number to 1 new switch (you really don't need this step as 1 is default already).

3) Turn off the master switch (this is the one you are planning to replace). Now one of the other 2 switches will be the master

4) Add the new switch to the stack and turn it on. 

5) once stack is in sync change master back to previous one and reload the stack

HTH

[aakash-agarwal]

Thanks :) So say my current master was with Priority of 14 and when i turn off my master other member with 10 Priority takes master role. now if i put back the new switch with out having priority default to 1 it will sync config and come back online with priority as 15? won't it try to take over? I am just worried if that would wipe of existing config. 

[aakash-agarwal]

Thanks :) So say my current master was with Priority of 14 and when i turn off my master other member with 10 Priority takes master role. now if i put back the new switch with out having priority default to 1 it will sync config and come back online with priority as 15? won't it try to take over? I am just worried if that would wipe of existing config.

[Reza Sharifi · Accepted solution]

Hi,

So say my current master was with Priority of 14 and when i turn off my master other member with 10 Priority takes master role.

That is correct.

now if i put back the new switch with out having priority default to 1 it will sync config and come back online with priority as 15?

No, you want the new switch to be the default (1).  After replacement, whichever switch has priority 14 will still be the master.

Now, once the new switch boots up all the way, you change the new switch priority to 15, save config and reboot the stack and the new switch should be the master now.

HTH

[aakash-agarwal]

thanks :) 

[haininghuang3185]

Hello, I would like to know whether preemption will occur after the new switch joins the stack group with priority 15？

[Joseph W. Doherty]

It does not preempt an active master.