difference between 0x2102 and 0x2101

johnifanx98

I read with boot field as 0x01, a mini-iOS image will be loaded. How mini is it, and what is the purpose to load such a mini-iOS?

clarson

not quite.

If boot field = 0, use the ROMMON OS.
If boot field = 1, load the first IOS file found in flash memory.
If boot field = 2-F:
A. Try each boot system command in the startup-config file, in order, until one works.
B. If none of the boot system commands work, load the first IOS file found in flash memory.

but if you have something as old as a 2500 router, rxboot with be loaded instead of rommon.

perform some troubleshooting, to recover router passwords, and to copy new IOS files into flash
when flash has been inadvertently erased or corrupted

d4nz1g

Use of the Configuration Register on All Cisco Routers - Cisco