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Wednesday, May 30, 2012

Cisco 1941 K9 - password recovery steps

What are the steps to recover password in a  Cisco 1941 K9?

Perform these steps in order to recover your password:

1) Attach a terminal or PC with terminal emulation to the console port of the router. Use these terminal settings:
Refer to these documents for information on how to cable and connect a terminal to the console port or the AUX port:
  • Cabling Guide for Console and AUX Ports
  • Connecting a Terminal to the Console Port on Catalyst Switches
  • Connect a Terminal to Catalyst 2948G-L3, 4908G-L3, and 4840G Series Switches
  • 9600 baud rate
  • No parity
  • 8 data bits
  • 1 stop bit
  • No flow control
2) If you can access the router, type show version at the prompt, and record the configuration register setting. See Example of Password Recovery Procedure in order to view the output of a show version command.
Note: The configuration register is typically set to 0x2102 or  0x102. If you can no longer access the router (because of a lost login  or TACACS password), you can safely assume that your configuration  register is set to 0x2102.
 
3) Use the power switch in order to turn off the router, and then turn the router back on.

Note:
In order to simulate this step on a Cisco 6400, pull out and then  plug in the Node Route Processor (NRP) or Node Switch Processor (NSP)  card.
In order to simulate this step on a Cisco 6x00 with NI-2, pull out and then plug in the NI-2 card.
 
4) Press Break on the terminal keyboard a couple of times after you see the message program load complete, entry point: 0x80008000, size: 0x6fdb4c in order to put the router into ROMMON.
Note: The values of entry point and size are subjected to the routers.
If the break sequence does not work, refer to Standard Break Key Sequence Combinations During Password Recovery for other key combinations.
If unable to break into ROMMON mode, perform these steps:
Remove flash.
Reload the router. Router will end up in ROMMON mode.
Insert flash.
Perform standard procedure for password recovery.
 
5) Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash.
This step bypasses the startup configuration where the passwords are stored.

6) Type reset at the rommon 2> prompt.
The router reboots, but ignores the saved configuration.
 
7) Type no after each setup question, or press Ctrl-C in order to skip the initial setup procedure.
 
8) Type enable at the Router> prompt.
You are in enable mode and should see the Router# prompt.
 
9) Type configure memory or copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.
 Warning: Do not enter copy running-config startup-config or write. These commands erase your startup configuration.
 
10) Type show running-config.
The show running-config command shows the configuration of the router. In this configuration, the shutdown command appears under all interfaces, which indicates all interfaces  are currently shut down. In addition, the passwords (enable password,  enable secret, vty, console passwords) are in either an encrypted or  unencrypted format. You can reuse unencrypted passwords. You must change  encrypted passwords to a new password.
 
11) Type configure terminal.
The hostname(config)# prompt appears.
 
12) Type enable secret in order to change the enable secret password. For example:
hostname(config)#enable secret cisco

13) Issue the no shutdown command on every interface that you use.
If you issue a show ip interface brief command, every interface that you want to use should display up up.
 
14) Type config-register . Where configuration_register_setting is either the value you recorded in step 2 or 0x2102 . For example:
hostname(config)#config-register 0x2102

15) Press Ctrl-z or end in order to leave the configuration mode.
The hostname# prompt appears.
 
16) Type write memory or copy running-config startup-config in order to commit the changes.


Citation - This blog post does not reflect original content from the author. Rather it summarizes content that are relevant to the topic from different sources in the web. The sources might include any online discussion boards, forums, websites and others.

1 comment :

  1. comment utiliser un routeur cisco 1941 K/9 et un routeur cisco 1841 sur le meme réseau? merci

    ReplyDelete

 
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