Tag Archive for 2600

Recovering IOS on a 2600 Series

Lab Prerequisites:

  • You’ll need a Cisco 2600 Series router or greater that has a corrupt Cisco IOS image or NO IOS image at all. If you wish to simulate this lab you can erase the flash on your device and reboot. Please note that you’ll need to backup the Cisco IOS image prior to erasing it unless you have another image on hand that you wish to load onto the device.
  • A console connection to the device is REQUIRED
  • You’ll need a TFTP server installed on your PC to restore the image.

Lab Objectives:

  • Boot the Cisco router into ROM mode by breaking the boot sequence using the keystroke CTRL + Pause Break
  • Set the TFTPDNLD variables required to execute the procedure which include IP Address, Subnet Mask, Default Gateway, TFTP Server, TFTP Image name.
  • Execute the TFTPDNLD command and load the image into RAM using the -r switch.
  • Once booted into Cisco IOS, configure a router so that you may copy a Cisco IOS image from a TFTP server to Flash.
  • Once all necessary configuration is done copy the IOS image from the TFTP server to the flash.
  • After the copy has completed, reboot the router and verify that the image boots successfully.

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Cisco 2600 Series Password Reset

Lab Prerequisites:

  • A Cisco 2600 Series router or greater that has an unknown console or enable password.
  • An active Serial Console session to the device that you’re unable to log into.

 

Lab Objectives:

  • Break the boot sequence when powering on the Cisco 2600 Series router to place yourself in ROM monitor mode.
  • Change the configuration register to 0x2142 to make the router bypass the contents of NVRAM when booting then reset the router.
  • (Option 1) – Once booted, place yourself into privileged mode and copy the start up-config to the running config. Afterward, you may change the line password or enable password and write the configuration by to NVRAM by issuing the copy run start command.
  • (Option 2) – Once booted, place yourself into privileged mode and do a write erase to clear the contents of the NVRAM.
  • Now change the configuration register back to 0x2102 to boot set the router to boot normally and load the NVRAM contents upon boot.
  • Now change the configuration register back to 0x2102 to boot set the router to boot normally and load the NVRAM contents upon boot.

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