Cisco IOS Router Password Recovery

This topic is to discuss the following lesson:

When you login to a router or switch how can you tell if someone applied the confreg 0x2142 command,but didn’t set the device back to the config-register 0x2102?

Hello Jack.

Using the show version command, you can see what the current configuration of the config register is. It’s usually the very last line in the output of the command. Take a look at the attached image that shows the output of the command.

I hope this has been helpful!

Laz

Is it possible to perform password recovery without losing configurations?

Alexis,
Yes, the standard procedure for recovering a password does not cause you to lose your startup configuration information. The exact procedure differs slightly for different products, so I will use a 2900 series router as an example below.

A high level overview of the process is:
-Attach the terminal cable to the console port
-Reboot the router and issue a BREAK during the boot
-Change the configuration register so that the device boots to ROMMON (usually 0x2142)
-Issue the Reset command at the rommon> prompt
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Important Step for your Question:
-Copy startup configuration to running configuration (make sure you do NOT reverse this!!). This step loads your saved configuration into active memory, but since you are already in the privileged mode, you have essentially bypassed any security associated with the startup config.
*******************
-Set the passwords that were lost
-Change your config-register back to the default (probably 0x2102)
-Issue a Write Memory to save your password and config register changes
-Reboot the device

Here is a more detailed Cisco Article:
http://www.cisco.com/c/en/us/support/docs/routers/2800-series-integrated-services-routers/112033-c2900-password-recovery-00.html

Hi,

So it is correct that once we reboot the router in ROMMON mode - start-up config will be intact ?

Thanks
Abhishek

Hello Abhishek.

Yes, that is correct. The startup-config remains intact when you boot the router in ROMMON mode.

Laz

Hello Rene,

Could you please provide the steps to recover the switch password?

Thank you.
Swapnil

Hello Swapnil

You can take a look at this lesson for the recovery of a password from an IOS router. The procedure is very similar for a switch.

You can also look at this Cisco documentation for more information.

I hope this has been helpful!

Laz