Quick Question on 3750 Switch Failure in Stack.

Answered Question
May 25th, 2010
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It appears my master switch in my 3750 stack has failed and I am replacing it today.  Besides getting the IOS version up to similar code as the rest of the switches, is there anything specific I need to do to replace this unit in the stack? 

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Correct Answer

Wipe the config of the new unit and place it into the stack, UNPOWERED.  If you connect the switch powered into the stack you will force a re-election and you will lose the stack connectivity until it's complete.

The new switch will not be master - until you make it the master, or the other units fail.


mparella Tue, 05/25/2010 - 09:08
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Gotcha.  Appreciate your help.  Does this plan work?

1. Wipe config on new switch.

2. Power entire Stack down.

3. Connect the new switch via stackwise.

4. Power the switches up (with the new one being powered last)

OR are you saying this can be done with a "hot" stack as long as the new switch is powered down when you add it?


OK - let me put some more meat on it:-

1. Wipe config on new switch - ONLY if you have been messing around with it, if it's straight out the box, no need - cable it up.

2. Power entire Stack down - no need to, stackwise was created for hot swapping stack members

3. Connect the new switch via stackwise - this has to be done regardless!

4. Power the switches up - you should only power up first the one you want to be master first, then the rest from a complete restart.  This also depends on the priority config for each memeber that you have configured.

I suggest you just take the replacement switch out the box, cable the stackwise cables into it.  once all cabling complete - then power the new unit.  No need to power the whole stack down.



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