Thursday, December 25, 2008

Error on Cisco 805 boot (boot#..)

I use a small Cisco 805 as dhcp server in my house. After a power failure the system started with the following prompt:

user@user-desktop:~$ minicom

Welcome to minicom 2.3-rc1

Compiled on Dec 10 2007, 10:36:19.
Port /dev/ttyS0

Press CTRL-A Z for help on special keys

TinyROM version 1.4(1)
19:37 11/07/00
Copyright (c) 1998-2000 by cisco Systems, Inc.
All rights reserved.

POST .............. OK. 16MB DRAM, 12MB Flash.


Honestly don't know what this is and the commands available were:

boot# help
boot Execute image or CLI command script.
delete Deletes file-name from flash (8th delete is permanent).
disable Disable privileged commands.
echo Display arguments (to test CLI behavior).
enable Enable privileged or debug commands.
erase Erase deleted and invalid files from flash.
help Display help for command (* for all).
list List files currently in ram and saved in flash.
load Load saved boot environment from flash.
passwd Set or change the ROM password.
reset Reset console port to current parameters.
set Set boot environment values.
save Save boot environment or loaded file to flash.
show Show current or saved boot environment.
upload Load image or configuration data into RAM.
undelete Undelete file-name (maximum of 8 deletes & undeletes).

Luckily googling around I found this page from cisco: that shows what to do to recover the system.

The command "set" will show the device config and which file it will be use to boot. The output of the set command show that I didn't have any boot image.

boot# set
set baud =9600
set data-bits =8
set parity =none
set stop-bits =1
set console-flags =0
set mac-address =000B.BE48.D887
set unit-ip =
set serv-ip =
set netmask =
set gate-ip =
set pkt-timeout =4
set tftp-timeout =16
set boot-action =none
set file-name =""
set watchdog =off
set prompt ="boot"
set ios-conf =0xA0

The second command to use is "list" that shows what you have saved on the ROM. I could find the ios image preset to boot from. Using the "set" command you configure the router to boot using the cisco image like follows:

boot# list
Status Size Dev Name
------ 48K flash TinyROM-1.4(1)
---r-- 911 flash full-config
---r-x 7529K flash c805-xxxx-5.bin
4480K free 12288K total

The list showed the c805-xxxx.bin being present, using set I change the boot-action and file-name settings:

boot# set boot-action=flash
boot# set file-name="c805-xxxx-5.bin

Once done just use the "save" command to (guess...) save the configuration and finally "boot" to load the ios into memory.

boot# save
save: succeeded (0 seconds).
boot# boot
Accessing flash:c805-xxxx-5.bin

Booting "c805-xxxx-5.bin" ...,

After the "Booting c805......" message the system starts as normal.

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