Hacking the Linksys WRT54GL wifi router


This wifi router cum four-port switch was introduced by Linksys after the uproar caused by its decision to terminate the hackable WRT54G router and replace it with the WxRiver, closed WRT54G??.

It comes with a Broadcom wifi chipset, and 16MB RAM and 4MB Flash memory, which is enough to run the alternative Linux firmwares such as OpenWrt, DD-Wrt, or Tomato.

FWIW, the unit I used is version 1.1 (S/N starts with CL7B).


Default firmware

To access the factory Linksys embedded web server, you must connect a PC to any of the switch's four ports. The web server can be reached at, and the embedded DHCP server is off by default, so you must assign the PC a address manually. The default admin account has no login, and the password is "admin".

Once connected, if you want to be able to reach the Linsys embedded web server through its public Internet interface:

  1. Through the Setup > Basic Setup section, assign a static IP to its Internet interface, eg.
  2. Click on Administration > Management, change the default admin password, enable  "Remote Management", and hit "Save settings"

You should now be able to connect to from a PC located in the network.

Note that for a simple SOHO setup, where the Linksys is connected either directly to an ADSL modem or acts as a repeater to connect hosts to a primary router, you don't need to create any static route in the "Basic Setup > Advanced routing" section.

Upgrading to DD-Wrt

Flashing the firmware

  1. Connect the PC to the Linksys through any of the four ports of the switch
  2. Set the PC to use with the Linksys using
  3. Using Internet Explorer, upgrade to the latest firmware provided by Linksys
  4. Hardreset the unit ("push the reset button with your router powered on. Hold it for 30 seconds with the router powered on. STILL holding it, pull the power cord for 30 seconds. Still holding it, plug the router back in and continue to hold the reset button for 30 more seconds.")
  5. Download the Micro or Mini build of DD-Wrt (you can upgrade to a bigger build afterward)
  6. Wait five minutes for the unit to rebuild the NVRAM after it has been flashed
  7. Power cycle the unit by unplugging the power cord for 30 seconds, and plugging it back in
  8. Wait for the lights to return to normal usually about 2 minutes
  9. Hard reset again, wait, and log back into the web interface as root/admin. You should be prompted to change the password
  10. If you enable admin access through the Internet/WAN interface, make sure you hit the "Apply Changes"

Setting up the unit as wifi repeater bridge

Wireless repeater mode comes in two flavors: regular (hosts connected to the Linksys use the same network plan as the remote wifi router to which the Linksys connects), and "bridged" (hosts connected to the Linksys live in their own network).