Password Recovery
Cisco 2500 / 2600 Routers
Passwords are recorded in the startup-config file which is stored in NVRAM.
The key to password recovery is to prevent startup-config from being copied to
running-config during the boot process. Bit 6 of the Configuration Register may
be altered to prevent startup-config in NVRAM from being copied to running-config
in RAM during the boot sequence.
If the password is lost, the Configuration Register may be altered while the ROM
monitor mode. ROM monitor mode may be accessed by pressing the and
keys while the IOS is being loaded from flash memory.
While practicing on a functioning router, you may reboot from privileged mode by
simply typing reload.
router# show version
Cisco Internetwork Operating System Software
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read/Write)
Configuration register is 0x2142 (will be 0x2102 at next reload)
--------------------------------------------------------------------------------
Password Reset - Cisco 2500 Series
01) cycle power (with ENABLE mode = practice)
router# reload
02) press & keys
03) change config register to 0x2142
2500: > o/r 0x2142
2600: rommon 1> confreg 0x2142
2600: rommon 2> reset
04) begin boot process
> i
05) answer no to configuration setup?
Enter Configuration Setup? [y,n] n
or
CTRL+C
06) enable privileged EXEC mode
router> enable
07) recover configuration from NVRAM
router# copy startup-config running-config
08) enable global config mode
router# config terminal
09) configure new secret password
router(config)# enable secret class
10) restore config register to 0x2102
router(config)# config-register 0x2102
11) return to privileged EXEC
router(config)# exit
12) copy config to NVRAM
router# copy running-config startup-config
13)
router# reload
--------------------------------------------------------------------------------
Type o/r 0x42 at the router> prompt. This tells the router to boot from Flash
Memory without loading the configuration file. If you want to boot from ROM
instead, type o/r 0x41. However, booting from ROM allows you to only view the
encrypted password or erase the configuration. You cannot change the password.
Here is the link that points to all the password recovery procedures for all
the Cisco products through the 12000 series:
http://www.cisco.com/warp/public/474/index.shtml
Also, here is the link that helps you to find the break sequence for the
communication program you are using:
http://www.cisco.com/warp/public/701/61.html
--------------------------------------------------------------------------------
How do I reset the enable secret password using SNMP
There is lots of information to recover lost passwords on the Cisco Website.
Most, if not all, involve having console access to the router - but say the
router is on the other side of the world? Answer - Use 3 simple steps via SNMP.
1. Read the config to a tftp server…
"snmpset -c
.1.3.6.1.4.1.9.2.1.55.ipaddress.of.tftpserver octetstring "
2. Next edit the configuration substituting the new, plain text, enable secret
password and save it back to a tftp server on the same network as the router.
"enable secret "
3. Then tell the router to boot the config on your tftp server (tftp server
needs to be on the same subnet).
"snmpset -c
.1.3.6.1.4.1.9.2.1.50.ip.address.of.tftpserver octetstring "
And the new config is running, telnet to the router and try your new password.
Then copy the running config to startup.