IOS Upgrade for 4500X & 4948E

[umer zubairi]

Gents,

I've to upgrade the IOS of 4500X and 4948E switches but couldn't find the clear steps in Cisco's official documentations.

Versions selected to be used are:

(1) 4500X = 3.3.6E

(2) 4948E = 15.2.2E6

* Please note that I'd like to upgrade without ISSU as it sometimes causes issues on the catalyst series.

**Kindly, also let me know if the ROMMON is also required to be upgraded on both the nodes.

Looking forward to hearing from you.

[Leo Laohoo]

Kindly, also let me know if the ROMMON is also required to be upgraded on both the nodes.

The Release Notes will specifically mention if ROMmon upgrade is required or not.

but couldn't find the clear steps in Cisco's official documentations.

Copy the IOS files into the appliances, change the boot string, save the config and then reload.

[umer zubairi]

Thanks for quick response Leo, I was actually thinking of you as I know you've good command on the Catalyst boxes.

It'd be great if you can share the CLI commands to be used for both 4500X and 4948E series switches. In Cisco documents it's given always for the ISSU option.

[Iulian Vaideanu]

I usually do this (let's assume I'm upgrading a 4500X from 03.04.07.SG to 03.04.08.SG):

- "sh run | i boot_system" would show me the currently configured boot image (if none, the first available would be used) - I'd get "boot system flash bootflash:/cat4500e-universalk9.SPA.03.04.07.SG.151-2.SG7.bin"

- "conf t", "no boot system flash bootflash:/cat4500e-universalk9.SPA.03.04.07.SG.151-2.SG7.bin", "boot system flash bootflash:/cat4500e-universalk9.SPA.03.04.07.SG.151-2.SG8.bin", "boot system flash bootflash:/cat4500e-universalk9.SPA.03.04.07.SG.151-2.SG7.bin" (I'm configuring the new image (which I've previously uploaded to bootflash: and md5-verified) as the preferred boot image, keeping the old one as a backup)

- ctlr-z, "wr mem"

- if everything's well for a while, deconfigure the boot system statement for the old image, and also delete the old image from bootflash:

[umer zubairi]

Thanks Lulian, I do the same with my 4500E series boxes with Sup 7LE or 8E.

However, I think procedure is slight different in 4900 and 4500X series switches which I couldn't find in the Cisco documentation available online.

[Leo Laohoo]

Copy the IOS file from the TFTP server to the appliance:  copy tftp://<TFTP IP address>/<filename.tar> bootflash:

[umer zubairi]

Superb!

Thanks Leo, I concluded the steps please let me know if I missed something here

(1) copy tftp://<TFTP IP address>/<filename.bin> bootflash:

(2) boot system flash bootflash:/<filename.bin

(3) no boot system flash bootflash:/old filename.bin

(4) config-register 0x2102 Do I really need to change the config register in 4500X?

(5) wr mem

(6) reload

(7)Apply the same process on other unit (individually) and then configure the pair for VSS

[Leo Laohoo]

(3) no boot system flash bootflash:/old filename.bin

Put the old IOS back in as a back-up.  In case the new IOS doesn't boot up, the old IOS will be loaded.  

(4) config-register 0x2102 Do I really need to change the config register in 4500X?

Just check to make sure the config-register is 0x2102.  IF it is, then there's nothing to do.

[umer zubairi]

Thanks again Leo much appreciated your prompt support.

I check in the release notes of IOS XE 3.6.xE and it says ROMMON upgrade is needed to run the VSS on 4500X series nodes.

So what should I upgrade first, IOS or the ROMMON?

[Leo Laohoo]

So what should I upgrade first, IOS or the ROMMON?

There is a process where the upgrade of the ROMmon and the IOS can be done with just one step. 

Otherwise, the normal step is to upgrade the ROMmon first and then the IOS.

[umer zubairi]

It'd be great if you can share the process to upgrade the IOS and ROMMON in one shot. That'd be easy I guess.

[Leo Laohoo]

Upgrading the Supervisor Engine ROMMON with Telnet

Don't forget to rate our useful post(s).

[umer zubairi]

The release notes of IOS XE 3.6.xE say;

"If you are upgrading to IOS XE Version 3.6.0E and plan to use VSS, you must upgrade your ROMMON to IOS Version 15.0(1r)SG10".

Now I'm upgrading to 3.6.6E not to the 3.6.0E should I upgrade ROMMON or no need?

Kindly, let me know so we can conclude the discussion.

Thanks again for all your support. It really helped!!

[Leo Laohoo · Accepted solution]

Yes.  Upgrade ROMmon to SG10 (or later).

The logic behind this is because in the future, someone will not have the "presence of mind" and will, most likely, neglect to read the Release Notes carefully.  That person will attempt to upgrade the IOS and may not realize that the ROMmon needs to be upgraded beforehand.  Doing the ROMmon sooner (rather than later) will save someone a certain degree of screaming.

[Leo Laohoo]

Thanks for taking the time to rate our post(s), Umer.  :)