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New Member

Adding a new WS-C3750-24PS-S to an existing stack of 5 x 3750

I was asked if any precautions need to be taken when adding a new WS-C3750-24PS-S to a stack that has 1 x WS-C3750-24PS-S and 4 x WS-C3750-24tS-S:


I said that the new switch:

1. Must have the same IOS as the existing stack members which is c3750-i9-mz.121-19.EA1d

2. The priority of the new switch must be 1 since the current master is 1.

3. the vlan.dat of the new switch must be deleted before adding the new switch to the stack

4. The config of the new switch must be erased before the new switch is added.

Is there anything else I missed.

New Member

Re: Adding a new WS-C3750-24PS-S to an existing stack of 5 x 375

Current stack before adding the new switch shows:


sohpuras1#show switch detail


Switch# Role Mac Address Priority State


*1 Master 0011.20c1.8600 1 Ready

2 Slave 0012.0062.3080 1 Ready

3 Slave 0012.7f1a.ca80 1 Ready

4 Slave 0012.01b8.fd80 1 Ready

5 Slave 0012.4355.6f00 1 Ready

In this setup switch 5 is the top most switch and 1 is the bottom most switch in the rack. Switch 1 (bottom most) is the Master currently. Customer wants to make Switch 5 (top most) the master.

I said to turn OFF the entire stack and to turn ON only the top most switch. Then this switch will become the master. After that I said turn ON the other 4 switches.

Then when everything is stable to add the new switch for which he has rack space only at the bottom of the current stack and no space at the top of the current stack.

Since I am not sure of what I am saying (because I have not worked on these 3750 stacks a great deal) I said to plan an outage of a couple of hours, save current config of current stack and then start.

Of course I infomred the customer to follow the steps that I mentioned in the previous entry about IOS versions need to be kept in mind.

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