Upgrade cisco catalyst C9500-48Y4C 17.06.03 to 17.12.4

[gremling]

I have 2 Catalyst 9500-48Y4C switches in stackwise-virtual, running firmware version 17.06.03, and I want to upgrade to the latest available version (if I’m not mistaken, it is 17.12.4). I have read that there is a possibility to perform the upgrade using ISSU, allowing me to avoid service interruption. My question is, is it possible to upgrade between these versions? If it is not possible, how do you recommend performing the upgrade, given that I do not have separate management of the switches (since they appear as a single unit in stackwise-virtual)? Thank you in advance, and I look forward to your comments.

[Flavio Miranda]

@gremling 

This is from the release notes for 17.12. As we can see, the only recommendation is to ajust some commands if you are coming from 16.x which is older than your corrent version.

 We can not find anything preventing the upgrade you want to perform.

Before you begin

When upgrading from ...	Use these commands...	To upgrade to...
Cisco IOS XE Everest 16.5.1a or Cisco IOS XE Everest 16.6.1	Only request platform software commands	Cisco IOS XE Dublin 17.12.x
Cisco IOS XE Everest 16.6.2 and all later releases	On Cisco Catalyst 9500 Series Switches, either install commands or request platform software commands1. On Cisco Catalyst 9500 Series Switches - High Performance, only install commands2.

[Leo Laohoo]

Always raise a "proactive" TAC Case before any firmware upgrade using ISSU.  The TAC Engineer should be in a WebEx session and ready to immediately intervene if the ISSU goes wrong.