Password Recovery on a Cisco 2500 Series Router
If you have built a home lab (or are running really ancient hardware in production), you may find yourself in need of resetting the password configured on a 2500 series router. Depending on the router platform, the syntax is different. Here's how to do it on a 2500:
1. Reboot the router and send a break sequence to enter ROMMON mode. Break sequences can be sent using a Ctrl+Break key combination, or if you are on a system that doesn't have a break sequence, try using your terminal software to send a break sequence.
2. (optional) Type the letter O and hit enter. Record the existing setting, it's most likely 0x2102.
3. To reset the configuration register and have the router bypass the startup-config, type the following:
o/r 0x2142
To boot the router, type the letter i and hit enter.
>i System Bootstrap, Version 11.0(10c), SOFTWARE Copyright (c) 1986-1996 by cisco Systems 2500 processor with 14336 Kbytes of main memory
The router should load and ask you to enter the initial configuration bla bla bla. Skip it and go into config terminal and change the configuration register back to 0x2102 (or whatever it was in step 2 if different). The command to change the configuration register in global config mode is as follows:
router(config)#config-register 0x2102
You can also copy startup-config to running-config to load the config file, or you can just reboot.
Reference: Password Recovery Procedure (cisco.com)
Comments
Password recovery on a Cisco 2500 series router.
Hi Adam, just to add that after loading startup-config to running-config, the person would then need to change the password in running-config, save to startup-config before rebooting unless the person just wanted to see the password in running-config. Thanks for your post. Just borrowed a 2500 series router to practice on. It doesn't have ethernet or fastethernet interfaces. So sad..
Good Point!
You are Correct! I made the assumption people knew what to do once they've gained access to priviledged exec mode.
Once you gain access, don't forget to change the password (or just erase the startup-config).
Just to clarify
Cool tip. Always handy.
Just want to clarify the process, after changing the config register and the router has rebooted then:
1) Go to privilege Mode with the "enable" command
2) do "copy startup-config running-config". Instead of just erasing your startup config entirely.
3) Change the password "enable secret xxxxxx"
4) Change Config register back "config-register 0x2102"
5) Then do "copy running-config startup-config"
6) Reboot
Anyone still using these!!!
Understand if these are deployed in some ancient network that knowone dare touch, but for a home lab 26xx routers are so much more powerful and can be picked up for not much $ or £
2522 makes a great frame switch
I have a couple of these in a home lab. They're definitely slower than the rest of the gear I've got, but for a frame relay switch, the 2522 is perfect. Also, got a 2511 with the octal cables for a term server. Makes consoling into everything much easier than moving cables.
I've got one, does that
I've got one, does that count? ;-)
The only reason I posted this is to share the syntax on the password recovery since it's a little different than newer routers. I had to reset the password on an old one and had to look up the o/r stuff, so figured I'd share.
In my system i can't skip the
In my system i can't skip the initial configuration, why is that?