Table of Contents

This guide was written in the assumption, that you have some preknowledge about Cisco Networking.

Explanations:
config-register 0x2102 – boot normally (default configuration register setting)
config-register 0x2120 – boot into ROM Monitor (ROMMON)
config-register 0x2142 – ignore contents of NVRAM (startup-configuration)

Routers

Cisco 4221

  • Ensure the router is off and connected to power.
  • Turn on the router.
  • Start your console session
  • While the router is booting send a break signal.

When arriving at rommon mode enter the following commands:

rommon 1> confreg 0x2142
rommon 2> reset

The router will restart on its own. Once restarted, type:

en
conf t
config-register 0x2102
end
wr
reload

After the router restarts, it’s reset, and you can start configuring it.

Cisco 2901

This is largely the same as resetting a 4221 router, with the exception that the data is stored on a compact flash card, in the front of the router.

  • Ensure the router is off and connected to power.

  • Remove the compact flash card

  • Turn on the router.

  • Start your console session

  • While the router is booting send a break signal.

  • When arriving at rommon mode insert the compact flash card enter the following commands:

rommon 1> confreg 0x2142
rommon 2> reset
  • The router will restart on its own. Once restarted, type:
en
conf t
config-register 0x2102
end
wr
reload
  • After the router restarts, it’s reset, and you can start configuring it.

Switches

Catalyst 3560 & 2960

  • While the switch is powered on create a console connection.

  • Power off the switch.

  • While powering on the switch, hold in the MODE button on the front of the switch.

  • When the switch is powered on, write the following command.

flash_init
  • When the following text appears flash_init, write the following commands.
del flash:config.text
del flash:vlan.dat
del flash:private-config.text
boot
  • This will do the following:
    • Delete the config file
    • Delete vlan data
    • In somecases when configuring ports, the switch will save to private-config.text, so we will delete that too.
    • Boot the switch into it’s default mode.

Now you have successfully resetted the Switch.