3750 Stack switch IOS version mismatch

Unanswered Question
Dec 4th, 2008

I installed a new switch into a 3750 stack. The new switch has a different version of IOS on it than the rest of the stack. For some reason it won't up/downgrade to the correct version.

3750-STACK#sho switch


Switch# Role Mac Address Priority State


1 Member 000a.b811.3f00 1 Ready

*2 Master 000a.b844.cd00 1 Ready

3 Member 000a.b844.b600 1 Ready

4 Member 0017.9426.f300 1 Version Mismatch

Isn't the stack supposed to automatically make the new switch the correct version? Is there a way for me to manually initiate this?

I have this problem too.
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mihanlin Thu, 12/04/2008 - 12:35


There are some limitations with auto-upgrade as to why it doesn't upgrade. Please note:


The software on the master switch must be the same type of image (i.e. the new switch must be IP services if the master switch it IP services).

Also, for auto upgrade to work it must be a minor version mismatch.

In your case, the easiest way is to remove it from the stack and manually upgrade.

Alternatively, if you can access the flash flesystem from the master, upgrade it using TFTP. Do a show file system and dir the flash of member 4 to see if you have access to it.

rshum Fri, 12/05/2008 - 06:53

Thanks, I eventually upgraded the new switch in the stack with the following command

archive copy-sw /overwrite /destination-system

Takes awhile but it copied the image over from another switch in the stack.

ropethic Thu, 12/04/2008 - 14:40

I have run into this situation every time I implemented stackwise. I had to upgrade each swicth individually prior to joining the stack. I too, was under the impression that it should automatically upgrade to latest version. It is suppossed to, but have yet to see it work this way. I have personally installed 3750s at least a half-dozen times with same results. So I just upgraded each switch prior to stacking.

gnijs Fri, 12/05/2008 - 03:58

you can do it manually:

remove the image from unit 4:

> del /force /recursive flash4:

copy the .bin image from one of the other

switches to unit 4

> copy flash1:// flash4:

reload unit 4

> reload slot 4


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