Appendix; Configuration Register Settings - Cisco 2691 - VPN Bundle Router Hardware Installation Manual

Configuration Register
This appendix describes the factory default settings of the configuration register, and procedures for
changing those settings.
This appendix has the following sections:
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Configuration Register Settings

The router has a 16-bit configuration register in NVRAM. You can use the configuration register to
perform the following tasks:
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Table C-1
Table C-1
Bit
Number
00-03
06
07
08
09
OL-2171-06
Configuration Register Settings, page C-1
Changing Configuration Register Settings, page C-2
Configuring the Boot Field, page C-3
Enabling Booting from Flash Memory, page C-5
Set and display the configuration register value
Force the router into the ROM monitor (bootstrap program)
Select a boot source and default boot filename
Enable or disable the Break function
Control broadcast addresses
Load operating software from ROM
describes each configuration register bit.
Configuration Bit Meanings
Hexadecimal Meaning
0x0000-0x000F Boot field. (See
0x0040 Causes the system software to ignore the contents of
NVRAM.
0x0080 OEM bit enabled.
0x0100 Break disabled.
0x0200 Causes the system to use the secondary bootstrap.
This is typically not used (set to 0).
A P P E N D I X
Table C-2.)
Cisco 2600 Series Routers Hardware Installation Guide
C
C-1