A classic scheme for Cisco router password recovery

Cisco routers use a lot of users, at the same time there will be many problems, the password is forgotten or lost users are very common problems, so I studied the Cisco router password recovery of two methods, here to take out and share with you, hope for everyone useful. When a Cisco router forgets or loses the enable password, there are two ways to recover, depending on which series of routers you are using.





first Cisco Router password recovery method:





uses this method to restore the following Cisco Router password recovery: Cisco 2000 series, 2500 series, 3000 series, Cisco 4000 series using 680x0 Motorol a CPU, running 10.0 version above Cisco The 7000-Series router for the iOS system.





1. Connect a terminal at the console port of the router or a PC that installs the emulation terminal software.





2. Enter the show version command, and then note the register value, usually 0x2102 or 0x102. This value is displayed on the last line, noting whether the Register's configuration sets the break to enable or disable.





The default configuration register value is 0x2102. This value is from the left and the third number is disable if it is 1, and if zero, the break is enabled.





3. Turn off the power and reboot.





4. Press the break key on the terminal within 60 seconds of the router's startup. The rommon> prompt is displayed. If the prompt is not the case, the terminal does not issue the correct interrupt signal to check whether the break key is correct or is set to disable.





5. At the prompt, enter o/r0x42 or o/r0x41,o/r0x42 meaning to boot from the flash memory, o/r0x41 to boot from ROMs (note that the first character is the letter O, not the number 0). Preferably with 0x42, in the case of flash memory or erase, only use 0x41, if there is 0x41 can only view or erase configuration, can not directly change the password.





6. Enter the initialization command at the rommon> prompt.





7. Enter the System configuration dialog prompt to knock No, always wait for the prompt to show: press RETURN to get started!





8. Hit Enter, the router> prompt appears.





9. Enter the Enable command, and the router# prompt appears.





10. Select one of the following options:





If the password is not encrypted, directly with more Nvram:startup-config command can see the password, in the case of password encryption, can not see, only modify, enter the command as follows:





Router # Configure memory





Router # Configure terminal





Router (config) # enable secret 1234ABCD





Router (config) # ctrl-z





Router # Write Memory





11. Enter configure terminal into configuration mode at the exec prompt. Enter the Config-register command to restore the register value recorded in the second step.





12. Knock Ctrl-z, exit configuration status.





13. In privileged mode, save the configuration with the Write Memory command, and then reboot reboot.





second Cisco router password recovery method:





Using this method, the following Cisco router passwords can be restored: Cisco 1003, 1600 series, 3600 series, 4500 series, 7200 series, 7500 series and IDT orion-based routers, the first four steps are the same.





5. At the rommon> prompt, enter the Confreg command.





do your wish to change configuration[y/n]?





Enter Yes and then enter. Always select no until you answer the question, until "Ignore system config info[y/n" appears? When you enter Yes. Then continue to knock no answer, until you see "Change boot characteristics[y/n]?" When you enter Yes.





Enter to boot: There are 2 and 12 options available at this prompt. If the flash memory is erased select 1, you can only view or erase configuration and cannot modify password directly. The best choice is 2. The following prompts appear:





do your wish to change configuration[y/n]?





answer No, then enter and show "rommon>".





6. Enter the reload command under the privileged exec.





back operation with the first method of