upgrading ios on 4500 Supervisor II+

[Kevin Melton]

I am working at a client site and I need to upgrade the IOS running on a Single Sup II+ engine running in a 4500 Switch chassis. I have searched Cisco specific to the 4500 and I do not get anything back that is specific to performing an IOS upgrade on a Sup II+.

I had an issue with this the last time I tried it about a year ago. I want to make sure I do this properly this time.

[Edison Ortiz]

Please refer to this URL

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/release/note/OL_2170.html#wp457685

Regards

Edison.

[Kevin Melton]

Step 6 in this document references setting the config register to 2102. Why do I have to do anything to the config register? The switch is currently running right now on code 12.2(46)SG with no issues. I would not think I would need to change the config register, as I am not in a recovery situation.

Thanks Edison

Kevin

[Marvin Rhoads]

0x2102 is the default, telling the switch to load the IOS you have loaded into flash. The step is for completeness, if for some reason you are running in other than the default mode.

See http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a008022493f.shtml for a full explanation of config register settings.

[glen.grant]

If you don't change the register it won't load the code because 0x2101 which is the default says to load the first image it finds in bootflash:. Unless you delete the current image it will always load 12.2.46SG . Changing the register allows you to add the 2nd image into flash and then use a boot statement to point to the new image.

[Kevin Melton]

Thanks for your answer. I actually was planning on deleting the old code and only having it load the new code. That is why I was thinking that I probably did not need to adjust the config-register.

I remember in some disaster recovery situations, I have changed the config-register to 0x2142?... what does that tell it to do?

Thanks again

[glen.grant]

0x2142 tell it to load a default running config with nothing in it . Used for password recovery , you then do a copy start to run and then change the passwords and the config register rback to 0x2101 or 0x2102.

[Edison Ortiz · Accepted solution]

Kevin,

As others indicated, this step was included in the document to prevent customers from getting into rommon mode due to previous incorrect config register setting.

Regards

Edison.