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Dan Yatzeck
Beginner

Stack version mismatch - Catalyst 2960X FlexStack+

I am attempting to join two identical Cisco 2960X switches into a stack at a remote branch office.  I made sure both were running the same IOS version - 15.2(2)E5.  However when the remote technician connected the switches, the logs showed a version mismatch.

After getting the switch back, I confirmed the IOS version was an exact match.  However when I ran the command "show platform stack manager all", the Stack State Machine View is showing the version as 7.56.  The other switch is showing 1.56.

This does not make sense to me as the Cisco documentation states that the stack firmware is set on the IOS image, so if the IOS image matches then the stack version should match as well.  The minor version matches, but the major version is off.

To troubleshoot, I upgraded the switch showing version 7.56 to the latest recommended release, 15.2(2)E6.  During the IOS install, the output showed clearly that the stack firmware was 1.56.  However after the upgrade was complete, the show command still reports 7.56.

Does anyone have experience with this at all to explain what is going on and how I can get the firmware to match?

1 ACCEPTED SOLUTION

Accepted Solutions

As long as you have the same exact software installed, it should work.

Can you provide the output of "sh ver" and "sh switch detail" from both switches?

View solution in original post

11 REPLIES 11
Reza Sharifi
Hall of Fame Expert

When you say "View is showing the version as 7.56.  The other switch is showing 1.56."

Are you referring to hardware version? If yes, you can't upgrade the hardware version and as long as the IOS matches stacking should work.

HTH

Here are some more details.

As you can see from the following details, the stack major version does not match.

Switch #1

Switch# show platform stack manager all

<snip>

                 Stack State Machine View
==============================================================

Switch   Master/   Mac Address          Version    Current
Number   Member                          (maj.min)  State
-----------------------------------------------------------
1        Master    9c57.ad73.d280          7.56        Ready

Switch #2

Switch# show platform stack manager all

<snip>

                 Stack State Machine View
==============================================================

Switch   Master/   Mac Address          Version    Current
Number   Member                          (maj.min)  State
-----------------------------------------------------------
1        Master    c4b9.cd57.b380          1.56        Ready

Here is an excerpt from the configuration guide:

Stack Protocol Version

Each software image includes a stack protocol version. The stack protocol version has a major version number and a minor version number (for example 1.4, where 1 is the major version number and 4 is the minor version number). Both version numbers determine the level of compatibility among the stack members. You can display the stack protocol version by using the show platform stack manager all privileged EXEC command.

Switches with the same Cisco IOS software version have the same stack protocol version. Such switches are fully compatible, and all features function properly across the switch stack. A switch with the same Cisco IOS software version as the stack master can immediately join the switch stack.

If an incompatibility exists, the fully functional stack members generate a system message that describes the cause of the incompatibility on the specific stack members. The stack master sends the message to all stack members.

Major Stack Protocol Version Number Incompatibility Among Stack-Capable Switches

Switches with different major Cisco IOS software versions usually have different stack protocol versions. Switches with different major version numbers are incompatible and cannot exist in the same switch stack.

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/stack_manager/configuration_guide/b_stck_152ex_2960-x_cg/b_stck_152ex_2960-x_cg_chapter_010.html

So my question is this - if the stack protocol version is tied to the IOS version, and the IOS version is an exact match, why are the stack protocol versions different between these two switches?  Or is there another way to re-flash the stack firmware?

Does anyone have any idea on this one?  If I can't get it working my only other option is to deploy these two switches as standalone and I'd rather not do that.

As long as you have the same exact software installed, it should work.

Can you provide the output of "sh ver" and "sh switch detail" from both switches?

View solution in original post

Wanted to provide an update on this one.

I ended up swapping out the switch for a new one and it's working fine.  There is some kind of issue with this one switch.

I tried installing all kinds of different IOS versions to get the stacking version to match. 15.0.2 works and shows up with the proper 1.55 stack manager version.  As soon as it is upgraded to 15.2 or above, stack manager shows 7.XX, and any attempts to stack with another switch show a version mismatch. (Another switch with identical software version shows major version 1, minor version 56 or above.  The major versions never match because this one is listed as 7.)

I don't know if this is a hardware issue or what, but for now leaving it at 15.0.2 and using it as loaner unit will work for my purposes.

Thanks for the update Dan!

Having this exact same issue, should I just RMA the switch?

I'm under the assumption now this is a problem not worth further troubleshooting, when I find a switch unable to join the stack, run a show platform stack manager all, if it shows a different version than the rest of the stack just RMA the switch

If the switch is not getting stack just because of the IOS version.

There r 2 options to get in the stack.

1) Remove the switch from a stack and upgrade it to the same version of the master switch.

2) If u don't want to remove from stack run the command software auto-upgrade enable 

 

BR

SM

This thread is about switches which were upgraded to the same version as the master but still won't join.

What is the solution for this? 
in my case stacking versions showing 1.59 for  one 2960 switch and 7.59 for the another 2960 switch.