Adding Switch To Stack

[tbenson340719]

I have never added a cisco switch to an existing stack before so I just want to make sure everything is done correctly. Currently we have three 3750-G switches stacked two 48 port and one 24 port, I want to add another 24 port to this stack.

I was not the one who originally installed these switches and do not have too much experience with cisco equipment but from what I have read I can set the priority for this switch and the master will configure it accordingly?

I included one screenshot of the stack and a physical picture of the stack, I also attatched our config.

[Amit Singh]

Hi Anthony,

There are a few things that you need to make sure before adding a switch to an existing stack. Please the configuration guide below on managing a switch stack :

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_25_se/configuration/guide/swstack.html

Cheers,

-amit singh

[tbenson340719]

Thanks for the documentation it has helped me  greatly. One Quick question though, I noticed that our switches are all set to priority 1 but one is set to master and the others member, if I leave the new switch at priority one when adding it will it become a member automatically?

Also we do have VLAN trunking on our network, should this device be in transparent mode when connecting?

[Nathan Spitzer]

Q: I noticed that our switches are all set to priority 1 but one is set  to master and the others member if I leave the new switch at priority  one when adding it will it become a member automatically?

A: Yes, though I would pick which one I want to be master and secondary and set the priority appropriatly.

Q:Also we do have VLAN trunking on our network, should this device be in transparent mode when connecting?

A: Doesnt matter, when it is added to the stack it ceases to have its own identity and takes on the identity of the stack. Think Star Trek Borg "resistance is futile, you will be assimilated". Once its added to the stack you log into the stack like normal and configure the new interfaces but whatever they are configured as now is gone. I normally wipe the config (write erase) of a switch before I add it to a stack. Just make sure its set to load the same software version and feature set as the rest of the stack and you should be good.

[tbenson340719]

Thanks for the reply, I just want to go over this one more time. I have 3 switches all are set to priority 1 and one is the current "master" the new switch to be added currently has a blank config and is set to priority 1 and role master. Should I be connecting this with role master or can I set it to member before connecting it?

Also I have read that since the stack ring configuration is full I can add this switch without shutting down the rest, do you suggest doing that or shutting them all down to do the work?

Sorry for all of the redundant questions I am still new to cisco IOS and just want to do things right, I appreciate all the help given.

[Nathan Spitzer]

Do this to set which chassis you want as master. This will also ensure adding a new switch cant mess up the stack:

1) Decide which switch I wanted to be master (hint: whatever is chassis 1) and run this command: switch priority 15

2) Decide which one I wanted to be secondary master (hint chassis 2): switch priority 14

I would do it during block time but no outage should be neccessary and you don't have to shutdown the existing switches. You should first read this section which details the two different cabling options, either of which will work.