Installation guide

APPENDIX

Cisco 4000 Series Virtual Configuration Register D-1

Cisco 4000 Series Virtual

Conﬁguration Register

This appendix describes the Cisco 4000 series virtual conﬁguration register, the

factory-default settings, and the procedures for changing those settings.

Virtual Conﬁguration Register Settings

The Cisco 4000 series has a 16-bit virtual register, which is written into the nonvolatile

random access memory (NVRAM). Use the processor conﬁguration register information

contained in this appendix to do the following:

• Set and display the conﬁguration register value

• Force the system into the bootstrap program

• Select a boot source and default boot ﬁlename

• Enable or disable the Break function

• Control broadcast addresses

• Set the console terminal baud rate

• Load operating software from ROM

• Enable booting from a Trivial File Transfer Protocol (TFTP) server

Table D-1 lists the meaning of each of the virtual conﬁguration memory bits.