Additional 3750 on the network

[said07]

I have a 3750 on the network. It is my only layer 3 switch and it is handling my vlans.
I am adding a second 3750 because we need more ports in the server room.
What would be the best way to go about doing that?
Should they be cascaded or not?

Thanks

 

[dgrizzard]

Stacking is the best way, just make sure they are the same series (G/E/X) and the same firmware version when you add the new one to the stack. I would also make sure your current switch has a higher priority so it is the stack master otherwise you could have some problems

 

[VinceWhirlwind]

First, get onto the CLI on your switch and make sure your logging is set to informational.

Then rack the new switch, patch in the stacking cables, and then power-up the new switch.

Now check your logs and you will see what it does. Generally, the master will upgrade the new switch to make it the same version. Sometimes you will need to make this happen by issuing the relevant commands. Either way, the logging will tell you what's happening and what you need to do.

 

[dgrizzard]

Should, yes I've had some Cisco and non-Cisco stacks not work the way they should when upgrading firmware and adding members.

 

[Viconsul]

Hi,

The best way forward is to ensure you get the same model as you currently have and use the Cisco stack cable supplied as already mentioned in the previous posts. The advantage of doing this is that, you will have all your ports available for client connections.
However, you have to ensure that the two switches are the same model and version. We recently added a new WS-C3750V2-48PS to our existing core stack of WS-C3750-48PS-S and it didn't like the version 2.

HTH

Viconsul

 

[said07]

Thanks guys. I start feeling little nervous about this. I read another post like mine and the infrastructure went south.
Lucky I have only one server room with one 3750.
I really appreciate everyone’s help. I will update as soon as possible.

 

[said07]

One more question please: What happens if the master takes a dive?

 

[Viconsul]

That should not happen but it always good practice to save your running configuration to a tftp server and in the unlikely event that you loose your master, you should be able to recover your running configuration from your backup.
You only have one switch at the moment and should the worst happen it means your network(vlans) are all gone but you can recover from your backup easily.

-Viconsul.

 

[dgrizzard]

Also, be aware that if/when you add another switch and the master does go down, the other switch will recognize this and takeover as the new master. The place where this is really relevant is if you are running any routing/SVI's off of this stack.

 

[VinceWhirlwind]

It won't take down your master.

The worst thing that you can do is reboot the master as you add the new switch. Don't do that.

Just add the switch and watch your logs (log to syslog for convenience). Sometimes it doesn't auto-upgrade and you get a message telling you you have to use the command:
archive copy-sw /overwrite /destination-system 2 1
( 1 is the source system)

 

[dgrizzard]

I think maybe I said that the wrong way, I meant when he has more than one switch and the master goes down. Not if the master goes down when he is adding a switch. Sorry if there was any confusion

 

[said07]

Finally I got to this project.
I did run a sh ver on both switches and found out:

The Cisco ios on the existing switch to be the master is ver 12.2 (35) Se5, Release Software (Fc1).
On the new switch it is ver 12.2 (25r) See4, Release Softeware (Fc1).

Do I need to downgrade the new swith to the same ver as the existing switch or what they have is close enough to work with no issues?

Thanks,

 

[vipergg]

Cant be new switches you are getting , the latest codes are like 12.2.54 . Those are very old codes you have on both .

 

[said07]

Am I safe to stack without touching firmware on the second switch?