What is the difference between a boot image and a normal IOS image

[admin_2]

I am looking to upgrade a 7100 router and am wondering what image to use. The current bootflash contains a .E5 extension and because of the size I am assuming it is a boot image. When I download a boot image from Cisco it has a .bin extension.

[#2]

In general, the boot image is a scaled

down image that is only used to assist

the router in booting up. Once the IOS

is loaded, the boot image no longer plays

a role. In general, you should not have to

upgrade the boot image unless told to

by a cisco rep. Most of the image on

CCO should be IOS images.