Reset Cisco Router Password
Ever been in a situation where you are on-site at a client’s location and need to get access to their Cisco router only to discover they don’t know the password? I know I have and today we are going to look at the steps to bypass and reset a Cisco router password.
First you will need a serial console connection to the router (To my knowledge there is no way to do this via telnet or ssh)
Step 1:
You will need to power off the router and power it back on. Immediately after powering the router on you will need to hit the CTRL + BREAK keys on the keyboard until you get into the ROMMON mode. You should now see the “rommon 1>” prompt.
Step 2:
In this step we are going to change the configuration register value. The default value is 0×2102, but we are going to change it to 0×2142. The 0×2142 register tells the router to ignore the startup-configuration. We do this with the following command:
rommon 1> confreg 0×2142
Now we need to reboot the router:
rommon 2> reset
After rebooting the router will boot with the initial configuration prompt type “no” to go on into the router command line.
Step 3:
Type “enable” at the command prompt to get into privileged mode. You should then see the “Router#” prompt.
Step 4:
We now need to load the startup-configuration into the running-configuration with the following command:
Router# copy startup-config running-config
Step 5:
Here we are going to go into the configuration mode and do the actual password change.
Router# configure terminal
Router(config)# enable secret yournewpassword
NOTE: At this point you can also change other passwords for telnet/ssh access, etc.
Step 6:
Lastly we need to put our configuration register back to the default value of 0×2102, save the configuration, and reboot the router.
Router(config)# config-register 0×2102
Router(config)# exit
Router# write mem
Router# reload
There you go! You now have full access to the router with a new password and the original working configuration.