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New Member

3750 stacking issue

I have two 3750 that are in a stack configuration, both came with 12.1(19) installed, which I am updating to 12.2(35).

"sh stack" shows both 3750's... switch1 is master, switch2 is member. Here's where I'm confused:

"sh flash" and "sh flash1" are identical down to the bit, and flash is where I've tftp'd the new IOS, which shows up in both flash and flash1. Now I'd like to up the new IOS to the other switch, but flash2 does not appear, regardless of my actions. From this tut ( ), it appears that I need to tftp the IOS.bin to both switches before I can run the "boot system switch all ... " command.

Any thoughts on producing flash2?

Much obliged,


Cisco Employee

Re: 3750 stacking issue

Hi Mike,

As you have 2 3750 so flash refers to 1st switch and flash 1 refers to flash of second switch. If you capture you complete upgrade process you will note that image is getting upgrade on flash as well as flash 1.

If you read STEP 10 "In order to verify that the new image is in flash for the stack members, issue the dir flash: command and the dir flash 1: command. In this example, there are two switch stack members. If the stack configuration includes additional switches in the stack, issue the dir flash#: command for each additional switch in the stack."



New Member

Re: 3750 stacking issue

"dir flash" and "dir flash1" showed the exact same contents, including the new .bin. So, I issued the "boot system switch all flash:/c3750...bin" command to cause both switches to load using the new ios.

Switch1 booted just fine, while switch2 came up in Version Mismatch mode... and since my new ios does not have crypto (the original did), auto-copy-software did not launch. It left me to connect directly to switch2 and loading via tftp.

All in all, not too much of a bother, just not the smooth process I made the mistake of hoping for.

If you can pick apart my description, I'd like to know where I went wrong for next time.


Re: 3750 stacking issue

In a stack flash: represents the flashn: of the master switch. If the switch 1 is the master, then the flash: is equal to flash1:.

If the master switch is switch 3, then flash: is equal to flash3:

In your case switch 1 is master, flash: is nothing but flash1:. once you copied the image to flash: manually copy the image to flash2: also.

You just need .bin image if you are managing switch using CLI. you can use Winzip or pkzip to open the tar image and extract the .bin. or you can download the .bin from

copy the image copy flash: flash2: