Catalyst 4507R+E ISSU update issue 03.11.07 -> 03.11.10

[sdet]

Hello,

a customer has two Catalyst 4507R+E chassis in an VSS cluster. The last year update to Version 03.11.07 with ISSU worked flawless.

This year the target was to move from 03.11.07 to the latest 03.11.10. But with the ISSU process we ran in an issue when the standby sub booted with 03.11.10. After establishing communications with the active sub, it discovered an "IOS version mismatch" and solved this with a restart and a boot of version 03.11.07.

%VSLP-5-RRP_ROLE_RESOLVED: Role resolved as STANDBY by VSLP
%C4K_REDUNDANCY-2-IOS_VERSION_CHECK_FAIL: STANDBY:IOS version mismatch. Active supervisor version is 15.2(7)E7 (cat4500es8-UNIVERSALK9-M). Standby supervisor version is 15.2(7)E10 (cat4500es8-UNIVERSALK9-M). Redundancy feature may not work as expected.
%C4K_REDUNDANCY-2-NON_SYMMETRICAL_REDUNDANT_SYSTEM: STANDBY:STANDBY supervisor will operate in fallback redundancy mode rpr.
%C4K_REDUNDANCY-3-COMMUNICATION: STANDBY:Communication with the peer Supervisor has been established
%C4K_REDUNDANCY-2-VS_REBOOT_ON_RPR_FALLBACK: STANDBY:Supervisor in virtual-switch configuration cannot operate in redundancy mode RPR, will be reset
%RF-5-RF_RELOAD: STANDBY:Self Reload. Reason: Virtual-switch fallback to RPR
%SYS-5-RELOAD: STANDBY:Reload requested by Platform redundancy manager. Reload Reason: Virtual-switch fallback to RPR.

The last mentioned version in the Compatibility Matrix is 03.11.09. No hint of the 03.11.10 to find. (https://community.cisco.com/t5/networking-knowledge-base/catalyst-4500-4900-series-issu-compatibility-matrix/ta-p/3899728)

Eventually we booted the standby directly to Version 03.11.10 without using the ISSU process, but we hit the same "IOS version mismatch" and needed to boot both chassis at once. This was very unlucky in an 24x7 environment.

We are done with this years update, but I worry about the next year when we might move to version 03.11.11 or 03.11.12. And the compatibility for ISSU is not clear.

I hope to get helpfull hints to solve this better next time.
Thanks for your time!

Regards
sdet

[DanielP211]

Hello!

The link referenced has not the latest documentation. I would always refer to release notes. 

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/release/note/ol-310xe-4500e.html

• Performing an ISSU from a prior release to IOS XE 3.6.0E is not supported.
  
  

So ISSU would work for you.
BR

[sdet]

Hallo DanielP211,

thanks for your reply.
Your link points to the 3.10.xE release notes from July 15, 2019.

I checked the current release notes (March 29, 2024). But I can not find a helpful hint regarding the compatibility.
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/release/note/ol-311xe-4500e.html#id_98232

But besides that ISSU should generally work (as it did last time). The hint to check the comp-matrix stored does not bring more clarity:

#show issu comp-matrix stored 

Number of Matrices in Table = 1

(1) Matrix for cat4500es8-UNIVERSALK9-M(232) - cat4500es8-UNIVERSALK9-M(232) 
==========================================
Start Flag (0xDEADBABE)

My Image ver:  03.11.07.E
Peer VersionCompatibility
-------------------------
03.12.00.EDynamic(0)
03.11.05.EDynamic(0)
03.12.01.EDynamic(0)
03.11.06.EDynamic(0)
03.12.02.EDynamic(0)
03.11.07.EComp(3)

The mentioned Compatibility Matrix was last edited on 09-13-2023.

Regards
sdet

[Reza Sharifi]

Hi,

Can you share the process you used when it didn't work?

I know that ISSU is a complicated process that sometimes works and sometimes does not.

That is why I always recommend performing any VSS upgrade during a maintenance window, as you never know what can go wrong.

HTH

[Leo Laohoo]

I believe 3.11.10 3.11.12 is the last release.  

Sup 8 end-of-sale date was on 30 October 2020 & end of SW maintenance date is 30 October 2021.  While end of vulnerablility/security support is still 31 October 2025, Cisco can/may change the date so they do not need to make any more releases after 3.11.10 3.11.12.

[sdet]

Hello,
@Reza Sharifi, we tried the 4 step ISSU process first.

issu loadversion 3 bootflash:/cat4500es8-universalk9.SPA.03.11.10.E.152-7.E10.bin 13 slavebootflash:/cat4500es8-universalk9.SPA.03.11.10.E.152-7.E10.bin forced

Failed with the mentioned "IOS version mismatch".
After that we tried it with changing bootvar but encountered the same issue.

boot system bootflash:/cat4500es8-universalk9.SPA.03.11.10.E.152-7.E10.bin
redundancy reload peer

 And were left with the need to boot both chassis at once.

@Leo Laohoo, sounds like I do not need to worry about another update, when there will be none. I already asked the customer how long they plan to use this EoL solution.

Regards
sdet

[Reza Sharifi]

The other thing is that starting October 2025, Cisco will not support the hardware anymore. So, the customer needs to think about the replacement options, as there is just over a year of support left for this platform.

HTH