How to restore the password of a Cisco Router

It is very important for Cisco router users to learn about commands for password recovery of Cisco routers. For many beginners, the ROM Monitor of Cisco routers is often unfamiliar or even daunting for a simple reason, first, we do not often use this mode and are not familiar with its related operations; second, Operation errors in ROM Monitor mode, it often causes fatal damage to the password recovery of the Cisco router, such as destroying the IOS file in flash, leading to system crash), so that many people are tolerance to it.

In fact, ROM Monitor is not complex. It is only a low-level operating system of the Cisco router, which is usually used for testing and troubleshooting. It can be done easily with little time. The following describes how to use ROM Monitor, which is the two most common problems for network administrators in actual work.

Cisco Router password recovery

To prevent others from knowing the vro password, especially the privileged password, and threatening local network security, many administrators have made the password particularly complex. However, after the vro is configured, we seldom operate on the vro. After a while, when we need to resume the configuration of the Cisco vro password, the password may be lost. At this time, we only need a PC operating system for the Windows series), a Console cable and the corresponding interface converter, and then follow the following operations, you can easily deal.

1. Set the Super Terminal of the PC so that we can use the Console port of the vro to directly operate the vro because the process is very simple. I will omit it to save space ).

2. Start the vro and press the Break or Ctrl + Break Key in the first 60 seconds to enter the ROM Monitor mode of the vro.

3. The following describes the Cisco 2600 series routers most commonly used by beginners.

Use this command to modify the value of the configuration register of the vro so that the vro does not load the startup configuration when it is restarted next time, so as to skip user password and privileged password verification and enter the privileged mode.
You must reset or power cycle for new config to take effect
Rommon 3> reset

Run the following command to restart the vro:
Wocould you like to enter the initial configuration dialog? [Yes/no]: n

Select no to directly enter CLI Mode
Press RETURN to get started!

Press enter to continue the next step.
Router> en
Router # show version

Use the show version command to check that the configuration register value is 0x2142.
Router # copy star run

Use this command to load the startup configuration and set a new password. If this step is not performed, the new password setting will fail after the next restart.
Router # conf t
Machine (config) # config-register 0x2102

The next restart of the vro will load the startup configuration. A new password is required for verification.
Router (config) # end
Router # copy run star

Save running configuration to startup configuration
Destination filename [startup-config]?
Building configuration...
[OK]

Tip: Password Recovery for Cisco 2500, 2000, 3000, 4000, and 7000 Series Cisco routers is basically the same as the above operations. The main difference is that the command for modifying the configuration register is "o/r 0x2142 ", and the restart command is "I". The vrouters of other series are basically the same as those of the 2600 series.