I forgot my username and password for a Cisco 2500 series switch.
How can I recover them?
Cisco maintains a page with links to the password recovery procedures for a lot of devices:
Complete these steps in order to recover a lost or forgotten password:
Attach a terminal or PC with terminal emulation to the console port of the router.
Use these terminal settings:
9600 baud rate
8 data bits
1 stop bit
No flow control
The required console cable specifications are described in the Cabling Guide for Console and AUX Ports (Cisco 1000 Series, 2500 Series, and AS5100).
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 usually 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.
Use the power switch in order to turn off the router, and then turn the router back on.
Press Break on the terminal keyboard within 60 seconds of power up in order to put the router into ROMmon.
If the break sequence does not work, refer to Standard Break Key Sequence Combinations During Password Recovery for other key combinations.
At the prompt, type o, press ENTER, and record the current value of the configuration register (usually 0x2102 or 0x102).
!--- Shows the configuration register option settings.
Configuration register = 0x2102 at last boot Bit# Configuration register option settings: 15 Diagnostic mode disabled !--- Output supressed.
Type o/r 0x2142, and press ENTER at the > prompt in order to boot from Flash and bypass the configuration file.
Type i at the > prompt, and press ENTER.
The router reboots, but ignores the saved configuration.
Type no after each setup question, or press CTRL + C in order to skip the initial setup procedure.
Type enable at the Router> prompt.
Once the Router# prompt appears, you are in enable mode.
Type configure memory or copy startup-config running-config in order to copy the NVRAM into memory.
Important: Do not type copy running-config startup-config or write memory. These commands erase your startup configuration.
Type write terminal or show running-config.
The show running-config and write terminal commands show the configuration of the router. In this configuration, the shutdown command appears under each interface, which means all interfaces are currently shutdown. Also, the passwords display either encrypted or unencrypted.
Type configure terminal, and make the changes.
The hostname(config)# prompt appears.
Type enable secret <password> in order to change the enable secret password.
Issue the no shutdown command on every interface that is used. If you issue a show ip interface brief command after you exit configuration mode, every interface that you want to use displays up up.
Type config-register 0x2102 (or use the value you recorded in step 4).
This step causes the router to load the Cisco IOS software from the Flash with the configuration from NVRAM at the next reload.
Press CTRL + Z in order to leave the configuration mode.
The hostname# prompt appears.
Type write memory or copy running-config startup-config in order to commit the changes.
Type Reload in order to restart the router and force the Cisco IOS software to boot from the Flash.