"Deep
in the sea are riches beyond compare.
But if you seek safety, it is on the shore."
Password
Recovery Techniques
Introduction
This
document will explain several password recovery techniques for
Cisco routers. You can perform password recovery on most of the
platforms without changing hardware jumpers, but all platforms
require the router to be reloaded. Password recovery can only
be done from the console port physically attached to the router.
There
are three ways to restore enable access to a router when the password
is lost. You can VIEW the password, CHANGE the password, or ERASE
the configuration and start over as if the box was new.
Each procedure
follows these basic steps:
1. Configure the router to boot up without reading the configuration
memory (NVRAM). This is sometimes called the test system mode.
2. Reboot
the system.
3. Access enable mode (which can be done without a password if
you are in test system mode).
4. VIEW or
CHANGE the password, or ERASE the configuration.
5. Reconfigure the router to boot up and read the NVRAM as it
normally does.
6. Reboot
the system.
NOTE: Some
password recovery requires that a terminal issues a
Break signal; you must be familiar with how your terminal or PC
terminal emulator issues this signal. For example, in ProComm,
the keys Alt-B will by default generate the Break signal, and
in
Windows Terminal you press Break or CTRL-Break. Windows Terminal
also allows you to define a function key as BREAK. From the terminal
window, select Function Keys and define one as break by filling
in the characters ^$B (Shift 6, Shift 4, and Capital B).
The
following six sections contain detailed instructions for specific
Cisco routers. Locate your router in the section headings to determine
which technique to use.
Technique
#1
All
Cisco 2000 Series, 2500 Series, 3000 Series, 680x0-Based 4000
Series, 7000 Series Running 10.0 or Later in ROMs, IGS Series
Running 9.1 or Later in ROMs
This
technique can be used on the 7000 and 7010 only if the router
has 10.0 ROMs installed on the RP card. It may be booting Flash
10.0 software, but it needs the actual ROMs on the processor card
as well.
1. Attach a terminal or PC with terminal emulation to the console
port of the router.
2. Type "show version" and record the setting of the
configuration register. It is usually 0x2102 or 0x102.
3. Power
the router down, then up.
4. Press the Break key on the terminal within 60 seconds of the
power up. You will see the > prompt with no router name. If
you don't, the terminal is not sending the correct Break signal.
In that case, check the terminal or terminal emulation setup.
5. Type "o/r0x42" at the > prompt to boot from Flash
or "o/r 0x41" to boot from the boot ROMs. Note that
this is the letter "o," not the numeral zero. If you
have Flash and it is intact, 0x42 is the best setting. Use 0x41
only if the Flash is erased or not installed.
NOTE: If
you use 0x41, you can only view or erase the
configuration. You cannot change the password.
6. Type "i" at the > prompt. The router will reboot
but will ignore its saved configuration.
7. Answer
"no" to all the setup questions.
8. Type "enable" at the "Router>" prompt.
You'll be in enable mode and see the "Router#" prompt.
9. Choose
one of these three options:
o To VIEW
the password type "show config."
o To CHANGE the password (in case it is encrypted, for example):
a. Type "config mem" to copy the NVRAM into memory.
b. Type "config term" and make the changes to the configuration.
conf t
enable password password
ctrl-z
c. Type "write
mem" to commit the changes.
o To ERASE the config, type "write erase.
10. Type
"config term" at the prompt.
11. Type "config-register 0x2102," or whatever value
you recorded in step 2.
12. Hit Ctrl-Z
to quit from editor.
13. Type
"reload" at the prompt. You do not need to write memory.
Technique
#2
Cisco 1003,
4500, or IDT Orion-Based Routers
1. Attach a terminal or PC with terminal emulation to the console
port of the router.
2. Type "show version" and record the setting of the
configuration register. It is usually 0x2102 or 0x102.
3. Power
the router down, then up.
4. Press the Break key on the terminal within 60 seconds of the
power up. You will see the "rommon>" prompt. If you
don't, the terminal is not sending the correct Break signal. In
that case, check the terminal or terminal emulation setup.
5. Type "confreg"
at the "rommon>" prompt.
6. Answer
"y" to the "Do you wish to change configuration[y/n]?"
prompt.
7. Answer "n" to all of the questions that appear until
you reach the "ignore system config info[y/n]?" prompt.
Answer "y."
8. Answer "n" to the remaining questions until you reach
the "change boot characteristics[y/n]?" prompt. Answer
"y."
9. At the
"enter to boot:" prompt, type "2" followed
by a carriage
return. If Flash is erased, type "1." If all Flash is
erased, the 4500 must be returned to Cisco for service.
NOTE: If
you use "1," you can only view or erase the
configuration. You cannot change the password.
10. A configuration summary is printed. Answer "n" to
the "Do you wish to change configuration[y/n]?" prompt.
11. Type "reset" at the "rommon>" prompt,
or power cycle your 4500 or 7500.
12. Once
it boots up, answer "no" to all the Setup questions.
13. Type "enable" at the "Router>" prompt.
You'll be in enable mode and see the "Router#" prompt.
14. Choose
one of these three options:
o To VIEW
the password type "show config."
o To CHANGE the password (in case it is encrypted, for example):
a. Type "config mem" to copy the NVRAM into memory.
b. Type "config term" and make the changes to the configuration.
conf t
enable password password
ctrl-z
c. Type "write
mem" to commit the changes.
o To ERASE the config, type "write erase."
15. Type
"config term" at the prompt.
16. Type
"config-register 0x2102" or whatever value you recorded
in step
2.
17. Hit Ctrl-Z
to quit from the editor.
18. Type
"reload" at the prompt. You do not need to write memory.
Technique
#3
IGS Routers
Running Software Earlier Than 9.1
IGS
routers have a bank of DIP switches on the rear panel. If they
are running software earlier than 9.1, then these switches are
used for password recovery.
1. Attach a terminal or PC with terminal emulation to the console
port of the router.
2. Power
the router down.
3. Record
the settings of the switches on the rear panel.
4. Set switch
7 ON (or down).
5. Set switches
0-3 OFF (or up).
6. Power
the router up. It will boot up to the > prompt.
7. Type "b"
at the > prompt. The router is in test-system mode.
8. Press
return until the "Test-System>" prompt appears.
9. Type "enable" at the prompt. You'll be in enable
mode and see the "Test-System#" prompt.
10. Choose
one of these three options:
o To VIEW
the password type "show config."
o To CHANGE the password (in case it is encrypted, for example):
a. Type "config mem" to copy the NVRAM into memory.
b. Type "config term" and make the changes to the configuration.
conf t
enable password password
ctrl-z
c. Type "write
mem" to commit the changes.
o To ERASE the config, type "write erase".
11. Restore
the switch setting to those recorded in step 3.
12. Reboot
the router.
Technique
#4
CGS, MGS,
AGS, AGS+, 70x0 Running ROMs Lower Than 10.0
1. Attach a terminal or PC with terminal emulation to the console
port of the router.
2. Power
the router down.
3. Remove the processor card (CSC/2 or CSC/3 or CSC/4 on AGS/CGS/MGS,
or RP on a 70x0).
4. Change the hardware register from bit position 0 (or 1) to
position 15.
5. Re-insert
the processor card.
6. Power
the router up.
7. Press
"b" at the > prompt or "b flash" if you
have Flash memory
installed.
8. Press
return until the "Test-System>" prompt appears.
9. Type "enable" at the prompt. You'll be in enable
mode and see the "Test-System#" prompt.
10. Choose
one of these three options:
o To VIEW
the password type "show config."
o To CHANGE the password (in case it is encrypted, for example):
a. Type "config mem" to copy the NVRAM into memory.
b. Type "config term" and make the changes to the configuration.
conf t
enable password password
ctrl-z
c. Type "write mem" to commit the changes.
o To ERASE
the config, type "write erase."
11. Power
the router down.
12. Remove the processor card and return the jumper on pin 15
to its original position.
13. Power
the router up.
Technique
#5
500-CS Communication
Servers
The
password cannot be recovered from the 500-CS since it does not
have a console port. Your only option is to erase the configuration.
1. Power
the router off by unplugging it.
2. Depress
and hold the DEFAULT button on the front of the chassis.
3. Power
the router back on.
4. Watch
the OK and LAN LEDs. They will blink on, and then off.
5. When they blink off (after about 15 seconds), release the DEFAULT
button.
6. In 2-10 minutes, the 500-CS will enter setup mode as if it
was factory new.
7. Configure
the router.
You
could also recover a password on a 500 by holding the DEFAULT
button down for 30-45 seconds. The system will then be in test
mode, and you can follow the normal procedure for password recovery.
See the earlier sections for details.
Technique
#6
Cisco 1020
You
must call the Cisco TAC to recover Cisco 1020 passwords. The 1020
will issue a password override challenge that can only be interpreted
by TAC personnel. |