Cisco 1841 V05
Start the console session.
Plug in serial cable to device from PC COM1 port
Open PuTTY and select "Serial" connection type, leave baud rate (Speed) and other settings as default.
Plug power into device and if a power button exists, turn it on.
Access the Rommon prompt.
Repeatedly press the Break key. Example output:
Readonly ROMMON initialized program load complete, entry point: 0x8000f000, size: 0xcb80 monitor: command "boot" aborted due to user interrupt rommon 1 >
TIP: If your keyboard does not have a Break key, in PuTTY right-click the titlebar for the dropdown menu -> Special Command -> Break.
Bypass any configured login.
Type the confreg command followed by a string value instruction to ignore the current configuration when booting up:
rommon 1 > confreg 0x2142 You must reset or power cycle for new config to take effect
Type the reset command:
rommon 2 > reset System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1) Technical Support: http://www.cisco.com/techsupport Copyright (c) 2006 by cisco Systems, Inc. PLD version 0x10 GIO ASIC version 0x127 c1841 platform with 131072 Kbytes of main memory Main memory is configured to 64 bit mode with parity disabled
The boot process should bring you to an initial configuration dialog prompt. Type n then the Enter key, and Enter again when prompted to get started:
Would you like to enter the initial configuration dialog? [yes/no]: n Press RETURN to get started!
Erase any log files, vlan data and all configuration settings.
Type the enable command to enter privileged command mode, then the dir command, then the del command with * where necessary to match multiple filenames listed:
Router>enable Router#dir Directory of flash0:/ 1 -rw- 16958152 Oct 14 2008 00:38:54 +00:00 c1841-spservicesk9-mz.124- 8.bin 31932416 bytes total (14970880 bytes free)
Type the erase startup-config command, and confirm with y:
Router#erase startup-config Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]y[OK] Erase of nvram: complete
TIP: You can verify vlan data and configuration is gone with the show vlans and show startup-config commands respectively:
Router#show vlans No Virtual LANs configured. Router#show startup-config startup-config is not present
Reboot the device and set it back to normal mode.
Type the reload command and confirm with y:
Router#reload Proceed with reload? [confirm]y *Oct 5 22:01:00.243: %SYS-5-RELOAD: Reload requested by console. Reload Reason: Reload Command.
Send the router a Break command again as done in step 2, then at the rommon prompt type the confreg command followed by a different string value instruction to no longer ignore the configuration:
rommon 1 > confreg 0x2102 You must reset or power cycle for new config to take effect
Lastly type the reset command:
rommon 2 > reset
Copy all the output from the session into your records.
Right-click PuTTY's titlebar, from that dropdown menu click on "Copy All to Clipboard"
Open the file of record certifying the deconfiguration of this device and use CTRL V to paste all the output from PuTTY into that file. Formatting the text with a fixed-width font helps it look more readable.
End the session.
Turn off/unplug the device and close PuTTy.