Cisco Systems OL-11497-03 manual Action/Filename Bit

Chapter 4 Troubleshooting the Installation

Performing Other Configuration Tasks

Note If a bootable Cisco IOS software image exists in a Flash memory card installed in PCMCIA slot 0 or 1, the configuration register setting is overridden, and the bootable Cisco IOS software image will be booted instead of the default TFTP-bootable Cisco IOS software image (cisco2-grpthrough cisco17-grpor cisco2-prpthrough cisco17-prp).

Table 4-3	Default Boot Filenames
Action/Filename		Bit 3	Bit 2	Bit 1	Bit 0
Bootstrap mode		0	0	0	0
Default software		0	0	0	1
cisco2-grp or cisco2-prp		0	0	1	0
cisco3-grp or cisco3-prp		0	0	1	1
cisco4-grp or cisco4-prp		0	1	0	0
cisco5-grp or cisco5-prp		0	1	0	1
cisco6-grp or cisco6-prp		0	1	1	0
cisco7-grp or cisco7-prp		0	1	1	1
cisco10-grp or cisco10-prp		1	0	0	0
cisco11-grp or cisco11-prp		1	0	0	1
cisco12-grp or cisco12-prp		1	0	1	0
cisco13-grp or cisco13-prp		1	0	1	1
cisco14-grp or cisco14-prp		1	1	0	0
cisco15-grp or cisco15-prp		1	1	0	1
cisco16-grp or cisco16-prp		1	1	1	0
cisco17-grp or cisco17-prp		1	1	1	1

The significance of bits 8 through 14 in the software configuration register follows.

	Cisco 12006 and Cisco 12406 Router Installation and Configuration Guide
OL-11497-03		4-9