Sunday, December 28, 2008

Lab 2 Reset Password of Router and Switch

Lab Section:  Router and Switch

Lab Title: Reset Password



1.       Understand how to reset the password of Cisco Router.

2.       Understand how to reset the password of Cisco Switch.



1.       Usually the switch and the router were given very complex passwords, and we forgot password for many reasons, but the start-config can not be deleted, in this situation, we need to reset the password and keep the start-config.

2.       The method of reset password for Cisco 2600 serial and 3600 serial is the same. There is a little different between 2500 and 2600/3600.

3.       For Switch, we need to get into “switch:” mode to reset the password: when you restart the switch, press “mode” key (located on the front panel of switch)





Reset 2600 serial router password (same as 3600 serial)

1.       Power on the router, in the meantime, press ctrl+break.

2.       rommon>confreg 0x2142

-- Change the start register value to 2142, it means the router will load the factory default configuration in the next start-up.

3.       rommon>reset

-- restart the router

4.       router#copy startup-config running-config:

-- Now we can enter the Privileged EXEC Mode, we need to copy the old startup-config which was saved in NVRAM to the current running config, remember we don’t want to lose the old configuration except the password.

5.       router#config t

6.       router(config)# enable password cisco.

-- After we copy the old startup-config, we also copy the old password, so we need to change it to a new password.

7.       router(config)#exit

8.       router#copy running-config startup-config

-- Save the current running-config which contains the new password to NVRAM

9.       router#conf t

10.   router(config)#config-register 0x2102

-- Restore the register value to 2102, it means router will load the configuration from NVRAM.

11.   router(config)#exit

12.   router#reload

-- Restart the router to check the password



Reset 2500 serial router Password:

1.       Power on the router, in the meaning, press ctrl+break.

2.       rommon>o/r 0x2142

-- Change the start register value to 2142, it means the router will load the factory default configuration in the next start-up.

3.       rommon>i

-- restart the router

The rest steps are as same as the 2600 router.



Reset Catalyst 2900 serial Switch password:

1.       Turn on the switch, in the mean time, press the “mode” button that located on the front panel.

2.       In the “switch:” mode, backup and rename the startup configuration.

3.       switch: dir flash:      ;check the current files in the flash, backup them if necessary.

4.       switch: rename flash:config.text flash:config_old.txt            ;Rename the configuration file, switch will use factory default setting if this file missing.

5.       switch: reset          ;Restart the switch

6.       Would you like to enter the initial configuration dialog? [yes/no]: n

7.       Enter the privilege EXEC mode

8.       Switch# copy config_old.txt running-config                ;copy the old configuration settings to running config, then we wouldn't lose the old settings.

9.       Switch# conf t

10.   Switch(config)#enable password cisco                ;Setup a new password

11.   Switch(config)#enable secret cisco12345

12.   Switch(config)#exit

13.   Switch#wirte                                      ;Save the new password to the start-up config

14.   Switch# reload               ;Restart the switch



1.       For more information, please visit my blog

2.       Video demo is located in


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