How do you recover a password of Cisco router ?

http://www.pateconsulting.com/how-perform-cisco-router-password-recovery-without-losing-your-configuration.htm

1Connect your router using console cable

2Restart your router

3Prss ctrl+pause break 

4Change confreg to0x2142

5Reset the router

6NO

7Enable

8Copy start run

9Config terminal

10Use password commands to chang or remove password

11Config_register0x2102

12Exit

13Copy run start 

have a look by here: 

http://www.cisco.com/en/US/products/hw/routers/ps259/products_password_recovery09186a.shtml

Reboot the router and press the break key to interrupt the boot sequence.Type config-register 0x2142.  This tells the router to bypass NVRAM during bootup.  In other words, your existing configuration won't be loaded,Type  reset to reboot the router.  Answer No when prompted to run setupType copy start run .  This loads your startup configuration into memory.  Now, if you type a show run config , you'll see the router configuration.  Also, you should notice that your router name is now in the prompt instead of the default “Router”

Change the enable secret - enable secret "new password" Change the register back to0x2102:config-register 0x2102 When the router reboots it will load the old configuration with the new password Save the password so that it will be persistent during reboots, type  copy run-start  Reboot the router by typing reload at the enable prompt.

If you do show version on the router Router#show versionYou will see on the last line of the output displayed on the console

      " Configuration register is0x2102 "This tells us that whenever router boots up then it will check its NVRAM for the startup configuration file, but if your locked out and not able to  get access on the router and not even on the enable mode i.e. Router> 

Then you need to reboot your router, by just powering off and on the Router and upon booting up you might see some output on the console some thing like this 

Self decompressing the image :

########################################################################## [OK]

Here IOS of the Router is being located and decompressed inorder to load it on your router's RAM so before it completely finish decompressing the image, hit Ctrl + c and then you would probably see a output on your console something like this 

Self decompressing the image :

#######

monitor: command "boot" aborted due to user interrupt

rommon1 > 

Now your in router's recovery mode called ROM Monitor modeSo here you need to tell the router that we need to change the bootup process of the router (register valve) to completely ignore the process of locating and loading the configuration file, so we type 

rommon1 >  confreg0x2142    

rommon2 > reset

 Upon resetting or rebooting the router you should see the router asking you to go SETUP MODE

         --- System Configuration Dialog ---

Continue with configuration dialog? [yes/no]: 

So now enter in the enable mode and type

Router>show version

to verify that your register value has been changed 

Configuration register is0x2142

You will see this on the very last line of the output

now go the enable mode and then configration mode  to change your password or whatever you want to do then save your configuration to the startup-configration file 

Router>en

Router#config

Configuring from terminal, memory, or network [terminal]? 

Enter configuration commands, one per line.  End with CNTL/Z.

Router(config)#enable secret Wat$Up

Router(config)#do wr

and now change the configuration register value back to its default value so that when you restart your Router again then it will check and load the configuration file

Router(config)#config-register0x2102

Verify it 

Router(config)#do show verison

So you should see the output something like this (on the very last line that is )

Configuration register is0x2142 (will be0x2102 at next reload)

Now your good to go, reload the router and Congratulations you have just recovered your Router's password.

I hope that answers your question. 

To change the current password without losing the configuration, you can use the following procedure . The interfaces will enter shutdown mode, it will return to the up .

1 ) Turn off and restart the router

2 ) During startup press Ctrl + Break (Windows , for other OS see the document Standard Break) or to get to the prompt " >"

3) Enter the following command:0x2142 confreg

4) Enter the following command: reset

5) At the re- start , the router will ignore the configuration file :Answer "no" to the questions he will ask .

6 ) Enter the enable mode with the command enable

7) Type the command: wr

8) Go into configuration mode : configure terminal

9) Change the enable secret password : new - password enable secret -password

10) Remove the password enable easy if there is : no enable password

11) Switch to Configuration Console Port: line con0

12) Change the password for the Console Port: password new - password -password

13) Exit the console port configuration mode : exit

14) Configure the router to normal startup via the command config- register0x2102

15) Exit the configuration mode : exit

16) Save the configuration : wr

17) Restart the router with the command reload