config-register 0x2101

[Cooky]

I know usually the normal confreg value is 0x2102, but recently we received a 4507R that was shipped w/ default value of 0x2101.

Looked it up on Cisco.com and the definition is the same as 0x2102, which is to boot IOS image from flash.

So...what's the difference betweeen the two?
Anyone knows?

 

[jlazzaro]

0x2102 boots according to the commands stored in NVRAM, 0×2101 boots into the RxBoot image stored in ROM.

0x2101 is the same as booting up with a 0x2102 but with the boot system rom in the startup config.

 

[Cooky]

thanks for the quick response.
Remind me again what the boot image does?
It's stored in ROM? I've never had to deal w/ it...can you even modify it?

 

[jlazzaro]

Some devices are designed to only boot from the first file in Flash. This makes it necessary to run an image other than that in Flash to upgrade the image, and that image is reduced command set image known as RxBoot (a ROM-based image).

However, I didnt think the 4500 was one of these devices. The only config register changes ive seen when upgrading 4500's (at least according to Cisco) is 0x2.