
If...
If you have a problem with accessing Cisco router cause forgotten the password, hope this tutorial will help you to find out how to fix it.

- If you can access the router, type show version at the prompt, and record the configuration register setting.
- 0x2102 boots and loads your saved configuration.
0x2142 boots and
by-passes the configuration and allows you to view/edit the save
configuration if you need to do any kind of password recovery, etc.
- Use the power switch in order to turn off the router, and then turn the router back on.
- Press Ctrl + Break on the terminal keyboard a couple of time after power up in order to put the router into ROMmon.
- Type confreg 0x2142
- rommon 1 > confreg 0x2142
- Type reset
- Type no in the intial cofiguration dialog
- Would you like to enter the initial configuration dialog? [yes/no]: no
- Do not type copy running-config
startup-config or write. These
commands erase your startup configuration.
- If you really want to restore your existing configuration,
- Type copy startup-config running-config
- Router#copy startup-config running-config
- Type configure terminal.
- Type enable secret
<password> in order to change the
enable secret password.
- Type config-register 0x2102
- Type write memory or copy
running-config startup-config in order to commit the changes.
Reference :
http://www.cisco.com/c/en/us/support/docs/routers/2600-series-multiservice-platforms/22188-pswdrec-2600.html