How to Break CISCO Router Password

Step 1
======

Reboot  the router.

At the time of rebooting press Ctrl + Break keys
                                             
Step 2
======

rommon 1 >confreg 0x2142
rommon 2 >reset


Step 3
======

Now router will skip the startup-confg file and reload without the password

Now you can change the password of your  router  from below commands


Change Console Password
=======================

router>en
router#conf t
router(config)#line console 0
router(config-line)#password CCNA
router(config-line)#login
router(config-line)#exit
router(config)#


Change enable mode Password
===========================
router>en
router#conf t
router(config)#enable secret CCNA


Step 4
======

Save the running-config into startup-config

router#copy running-config startup-config


Step 5
=======

Again change the configuration register value.

router#conf t
router(config)#config-register 0x2102
router(config)#exit
router#reload


That's it.