Stacking Question - 3750 and Different Image

[Ed Willson]

I've got 2 stacks of (2)3750 switches that I'd like to consolidate as the current implementation wastes a bunch of ports.  One stack is acting as the core switch for our main branch, the other is the SAN switch.  There is no connectivity between the SAN and Core switches at the moment.  I'm planning a DR site and need to route traffic from the SAN network to a remote site, and at the same time I'd like to reclaim the unused ports.  Both of these stacks are L2 only and don't utilize any routing.  Both are also not under support anymore.  So here's what's running on the stacks now:

LAN

Switch   Ports  Model              SW Version              SW Image           

------   -----  -----              ----------              ----------         

      1   28     WS-C3750G-24TS     12.1(14)EA1a            C3750-I9-M         

*    2   28     WS-C3750G-24TS     12.1(14)EA1a            C3750-I9-M   

SAN

Switch   Ports  Model              SW Version              SW Image           

------   -----  -----              ----------              ----------         

     1   28     WS-C3750G-24TS-1U  12.2(35)SE5             C3750-IPBASE-M     

*    2   28     WS-C3750G-24TS-1U  12.2(35)SE5             C3750-IPBASE-M

I know the hardware is compatible.  But what would be the process to negotiate the difference in Images with a minimum of downtime?  I'm not worried about downgrading a stack.  I'll also clean up the mess caused by the previous owner not setting priority

Thanks,

   Ed

[Ed Willson]

So after doing a couple hours reading today I think I'll upgrade the LAN stack to a version we have license to, and then downgrade the SAN stack to the same version.  Once they are all on the same version I'll stack the stacks and set my priority and reload everything.

Anyone have anything to say boo about in that basic plan?

Thanks,

    Ed

[lgijssel · Accepted solution]

You may also consider to upgrade all switches to the lastest version you posess: 12.2(35)SE5

After that you can merge the stacks together.

It may even be possible to trigger the upgrade after merging the stacks with their current versions but if you want to reduce your downtime, its probably better to do it on forehand.

Just one tip: Use the archive command for the upgrade instead of only copying the .bin file.

regards,

Leo