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New Member

upgrade stacked 3750

Don't think there is a way, but wanted to double check and see if there is a way to upgrade software on stacked 3750's without taking a hit.

  • LAN Switching and Routing

Re: upgrade stacked 3750

Hello Brian,

You anyway need to take a downtime, atleast 5-10 mins for this upload... archiving the software into the box, will not affect performance for the users, but once the IOS is uploaded onto the box, it does not directly take the OS as boot image.. you anyway need to reload the 3750's to activate the IOS images... i wouldnt say this as a big hit, but you can schedule and do this change !!!!

I'm attaching a very good doc, which will guide you through this upgrade.

Hope this helps.. all the best.. rate replies if found useful.



Re: upgrade stacked 3750


Upgrading the 3750 Stack is relatively easy. You just copy from tftp then to Flash1: do the same but from tftp to flash2: (Second switch) Once done isssue the reload command on the master. The master will reaload the whole switch stack.

Delete the old IOS before your reboot otherwise you have to specify which IOS the switch should reboot from.

Let me know if you need further clarification,

Appreciate your rating,


New Member

Re: upgrade stacked 3750

I found it easier to use Cisco Network Assistant to upgrade a software on IOS switches. You can build a cluster out of stacked switches, and then you can pick two or more switches at one to upgrade. TFTP upload takes much longer, but it works fine. In addition, CNA takes car about all upgrade changes (i.e. specifying correct "boot system" sequence).

Good luck,



Cisco IP Phone Headset Adapters

New Member

Re: upgrade stacked 3750

Thanks all, I might not have been clear enough in my first post; upgrading the software isn't the issue (we'll push the ios out with cisco works ahead of time so its ready to go); we were just looking for a way that the stack could be reloaded in a way that some of it would always be up. We have many critical devices attached to multiple stacks, most ether-channeled across the switches for maximum redundancy (so we can lose a switch, or a core switch behind them, and not take a hit to our end devices), but obviously upgrading software is going to cause a hit. Didn't think there was a way around it, but wanted to make sure.

Thanks again.


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