4-3
Cisco 12404 Internet Router Installation and Configuration Guide
OL-11636-01
Chapter 4 Troubleshooting the Installation
Performing Other Configuration Tasks
Table 4-1
Software Configuration Register Bit Value and Function
boot field
, which defines a source for
booting the default Cisco IOS software image required to run the router. The
content of the boot field is specified as a binary number.
Bit Number
1
1.
The factory default value for the software configuration register is 0x0102. This value is a
combination of binary bit 8 = 0x0100 and binary bits 00 through 03 = 0x0002.
Hexadecimal
Value
Function
00 to 03
0x0000 to
0x000F
Comprises the boot field for defining the source of
a default Cisco IOS software image required to run
the router.
06
0x0040
Causes system software to ignore the contents of
NVRAM
07
0x0080
Enables the OEM
2
bit
2.
OEM = original equipment manufacturer.
08
0x0100
Disables the Break function
09
0x0200
Uses a secondary bootstrap
10
0x0400
Broadcasts Internet Protocol (IP) with all zeros
11 and 12
0x0800 to
0x1000
Defines the console baud rate (the default setting
is 9600 bps)
13
0x2000
Boots the default Flash memory software if the
network boot fails
14
0x4000
Excludes network numbers from IP broadcasts
15
0x8000
Enables diagnostic messages and ignores the
contents of NVRAM
Table 4-2
Boot Field and Definitions
Boot Field
Definition
00
At power-on, the system remains at the ROM monitor prompt
(
rommon>
), awaiting a user command to boot the system manually.
01
At power-on, the system automatically boots the first system image
found in the onboard Flash memory SIMM on the RP.
todd.book Page 3 Tuesday, November 27, 2007 6:02 PM