Hi Sharifi

Thanks for the prompt reply.

From http://www.cisco.com/en/US/customer/docs/switches/lan/catalyst3750x_3560x/software/release/12.2_55_se/configuration/guide/swstack.html#wp1142379"

"The system-level features supported on the stack master are supported on the entire switch stack. If a switch in the stack is running the IP base or IP services feature set and the cryptographic (that is, supporting encryption) universal software image, we recommend that this switch be the stack master. Encryption features are unavailable if the stack master is running the IP base or IP services feature set and the noncryptographic software image."

Would it work if I set the new switch to be stack master?

Hi,

In stack environment, it is recommended to have the same image in all your devices and also have the same license level in all devices.  If you have IP services on the master stack and IP Base on the reset of the switches, the entire stack will be effected if the master fails, because not all the features are the same in IP services vs IP based.

HTH

Hi

Based on this line "If you have IP services on the master stack and IP Base on the reset of the switches, the entire stack will be effected if the master fails, because not all the features are the same in IP services vs IP based.",

If IP services are not used in the network i.e a simple edge switch, it won't matter if the 3750x (stack master) fails and a another switch takes over?  Because my main priority is to get the network up and running first.

Also, I've been checking out on the universal image vs IPB vs IPS... if the switch comes with just the universal image with no other information, can I assume that there were no additional license features purchased?

Would it work if I set the new switch to be stack master?

How can your switch be the stack master if it hasn't JOINED the stack yet due to IOS version mismatch?

What Reza's been telling you is THE recommended method. 

Hi leolaohoo/Reza

3750X - 12.2(55)SE3, Universal

- As I understand it, Universal image is a "basic" image that comes with all the features but you need to purchase a seperate license to enable the features that you require, i.e IP services

3750 - 12.2(25)SEE2 , IPServices

- L3 image (in a nutshell)

So, to make them stack, I have 2 options :

Either

1) Upgrade (or is this considered a downgrade?) the 3750x to 12.2(25)SEE2 , IPServices

OR

2) Downgrade (or upgrade?) the 4 x 3750 to 12.2(55)SE3, Universal?

Like I've mentioned, usually my colleague handles the licensing stuff. Are there any licensing issues if I copy the IOS from one switch to the other ? i.e Copy the image from a 3750 and get it on a 3750x or vice-versa?

1) Upgrade (or is this considered a downgrade?) the 3750x to 12.2(25)SEE2 , IPServices

Good luck on that.  You will NEVER be able to downgrade a 3750X to this level.

Recommendation:  Upgrade your 3750/3750G and 3750X to either 12.2(55)SE5 or 12.2(55)SE6. 

Hi leolaohoo

Am I right to say that I would need the following files :

For 3750x – download c3750e-universalk9-tar.122-55.SE5.tar

For 3750g – download  c3750-ipservicesk9-mz.122-55.SE5.bin

For 3750 – download c3750-ipservicesk9-mz.122-55.SE5.bin

Once they are on the same version, they should be able to stack together ?  I hope I'm getting this right

Yes that is correct.

I am in the same situation. I have a 3750X with the universal image. I think I'll make the version numbers all match but leave the Universal image on the X and then stack them together.

I've made exactly this work only yesterday, with a new switch stack I had to configure.

For 3750x – c3750e-universalk9-tar.122-55.SE5.tar

For 3750 – c3750-ipservicesk9-mz.122-55.SE5.bin

The stack sees all members and comes up fine.