In-depth introduction to Cisco router configuration

There are many knowledge about Cisco routers. Here we mainly analyze the specific methods for Cisco router configuration. Have you ever encountered this problem in daily network management and maintenance: You have been forcibly rejected by a vro or vswitch, a former "friend", because you forgot your password, parameter resetting and information statistics are not allowed.

The following describes how to clear passwords for several common and important network devices ". Applicable scope: All Cisco 10.0, 2000, 2500, 3000 and 4000 vrouters of IOS 7000 and later versions. The cleanup procedure is as follows:

1. Connect to the Console port with the serial line of the vro. The following is done through the Win95 Super Terminal;
2. After the router power-on 60 seconds, press CTRL (if not press the CTRL-BREAK) Key, waiting for the prompt ">;
3. type the "> e/s 2000002" command, and record the return value, which will be used in the subsequent "Router (config) # config-register 0x2102" command. (generally, the return value is 2102)
4. Enter "o/r 0x42" after the ">" symbol ";
5. Type "I" and the vro will be reinitialized. If you have any questions, answer No;
6. Type "Enable" (no password, press Enter );
7. Change the password (whether encrypted or not ):
A. Enter "config mem" or "copy startup-config mem ";
B. Enter "write ";
C. Enter "config term" and "enable secret <password>" and "enable password <password>" to change the password;
8. Remove the user prompt and password:
A. Enter the virtual line Cisco router configuration mode and enter "line vty 0 4 ";
B. Enter "password <password>" to change the password;
C. Enter "login" to remove the user prompt, Which is login local );
9. Press Ctrl-z to finish;
10. Enter "write" to save the changes;
11. Enter the privileged Cisco router configuration mode and type "config-register 0x2102" (note that this step must be completed );
12. Write to save the configuration information;
13. Exit the Cisco router configuration mode and Reload the router to restart it.

Note: o/r 0x42 is used to guide the router from Flash. If the router fails, you can use o/r 0x41 to guide the router from the ROM. Other operations are the same as o/r 0x42, however, it is best to use it only when Flash Boot fails, Flash content is deleted, or Flash content is not available. With 0x41, you can only view or delete Cisco router configuration information, but cannot change the password.

Clear Cisco router configuration information

1. When the switch is powered on and started, press and hold the Sys Req button on the back panel of the switch for 5 seconds, and then release it;
2. Go to the configuration menu and select "Clear Non-Volatile RAM" to Clear all Cisco router configuration information including passwords of the vswitch ).
3. reconfigure parameters and passwords as needed.

Clearing the Intel Express Switch password applies to Intel Express 10 Switch/10 Switch +/100FX Switch. Method 1:

1. Enter the Maintenance Mode of the vswitch Maintenance Mode), enter: run defparm to restart the vswitch, and change the original Cisco router configuration to the original default setting (the original default has no password ).
2. Enter the maintenance mode:
A. Close the vswitch and press the Maint button on the panel to power the vswitch;
B. Press the button to keep the System LED green light flashing for 3 seconds;
C. Release the Maint button.
3. Use the serial port of the switch to enter the switch in the terminal mode compatible with VT100 at 9600/N/8/1;
4. Press Enter until the command line prompt is displayed on the screen.