Cisco Systems Cisco 12816 Manuale Utente

The boot field (

) defines a source for booting a default Cisco IOS 

software image required to run the router. The content of the boot field is specified 
as a binary number.

 

A Cisco 12010, Cisco 12410, or Cisco 12810 router is shipped with a boot image 
in the boot flash, and a Cisco IOS image on a flash memory card.

The four low-order bits of the software configuration register (bits 3, 2, 1, and 0) 
form a boot field that defines the source of a Cisco IOS software image for booting 
the router.

You can set or change the contents of the boot field by entering the 
config-register command at the global configuration mode prompt 
[

Milo(config)#

]. 

The factory default configuration register setting for an RP is 0x0102.

00

System remains at the ROM monitor prompt (

rommon>

), awaiting 

a user command to boot the system manually.

01

System automatically boots the first system image found in the 
onboard flash memory SIMM on the RP.

02 to 0F

System boots automatically from a default Cisco IOS software 
image stored on a TFTP server in the network. This boot field 
setting requires that the Ethernet port on the RP is configured and 
operational. This setting also enables boot system commands that 
override the default filename.