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DD-WRT Beginners Router Firmware Flash Guide

Posted on January 22nd, 2016

This beginners guide is intended as a tutorial for people who’re unsure about flashing their router or have less computer experience.

The guide will show you, step by step, how to Flash the Buffalo WHR-G300N Router with the DD-WRT Firmware. Although I’ve used the WHR-G300N, you will be able to use the guide when flashing any Buffalo router with the DD-WRT firmware. The guide is for Windows XP and Vista, but can also be used for Windows 7.

If you already know a bit about this, understand what I mean by “ping” etc, then you may want to check out the Quick Guide.

Downloading the Firmware

First things first, we need to head over to http://www.dd-wrt.com and download the latest DD-WRT firmware. Click on the “Supported Hardware” tab and enter “WHR-G300N” (or whatever the model of router you have is).

You’ll see the model come up, so click on that link. Keep the “Supported By” pull down menu set to the default recommended option.

There are 2 different versions of the firmware available; “firmware.tftp” and “WHR-G300N-webflash.bin”. As this is first time you’re flashing the router we have to use firmware.tftp, download this and save it your c: drive (not in any folders).

The reason we can’t use the webflash version is due to Buffalo encrypting their firmware, so we have to hack into the router during its “Recovery Mode”. This is a simple process, but more about that later.

Once we have flashed with the DD-WRT firmware the first time, then we’ll be able to use the much simpler web interface to flash it, for any future updates.

TCP/IP Settings

DD-WRT TCP IP Settings

  1. Open Network Connections dialog, this can be done from Control Panel. Or for the lazy amongst us, open the Start Menu and choose “Run”, enter:

    Hit return. Note: in the Vista/Windows 7 menu, you may not see a Run option, just enter ncpa.cpl in the “Start Search” box

  2. You should see an option for “Local Area Connection”, Right Click and select “Properties”
  3. From the Properties dialog, select “TCP/IP Settings” (maybe called “Internet Protocol” in Vista/Windows 7) and hit the “Properties” button. If given a choice, its IPv4 you want and not IPv6.
  4. Enter the following IP Address details and hit “OK”.
    IP Address:
    Subnet Mask:
    Default Gateway:

It may take 20 or so seconds for the new settings to update.

Connecting up the Router

DD-WRT Router Connected

Everything you need will be in the router box.

  1. Take the router out the box, connect the power and plug it in. You should see lights at the front come on and start flashing. After around a minute it have booted.
  2. Connect one end of the suppled Ethernet cable to your PC’s (or Laptop or Netbook) Ethernet port – it will be the only port the Ethernet cable will fit in.
  3. Connect the other end of Ethernet cable to Port 1 on the Router.
  4. Make sure the “Router” Switch on the back of the router is set to “Auto”. If using a different model, there may not be a Router switch.

To check that the settings are OK and you can talk to the router, open your browser and enter the address as You should see the Buffalo firmware (username is “root” password is blank if you want to have a little play around).



Flashing the Router

DD-WRT Flashing Router TFTP

Now the fun part, flashing the router! We have the new firmware saved in the c: drive and the router is all connected up.

  1. Unplug the router.
  2. Make sure all Firewalls are turned off, including the Windows Firewall.
  3. Open a command prompt. To do this open the Windows Start Menu and select Run. Enter:

    Hit enter. Note: in the Vista/Windows 7 menu, you may not see a Run option, just enter cmd in the “Start Search” box.

  4. In the newly opened command prompt windows; enter the following:
    tftp -i put firmware.tftp

    Do not hit return. Note if using Windows Vista/Windows 7, the TFTP client may not be installed. From the run menu again run:


    This brings up the “Programs and Features” dialog. Select “Turn Windows features on or off”. Check the box “TFTP Client” and hit OK. You can now use the TFTP command.

  5. Power on the router.
  6. Within 3 seconds of powering on router, hit return on the command prompt. You should see:
    Transfer Successful...

    The reason we need to do this in the first 3 seconds, is this the router in “Recovery Mode” and the only time we can overwrite the encrypted Buffalo firmware. Thankfully we can use the web interface once the DD-WRT firmware is on there.

New TCP/IP Settings

The new firmware uses a different IP address. So we need to update the TCP/IP settings to a new range. It’s the same way we did it before, but a slightly different address.

Follow the instructions from the TCP/IP section above only this time enter the following IP Address details and hit “OK”:

IP Address:
Subnet Mask:
Default Gateway:

It may take 20 or so seconds for the new settings to update.

Finalising Install

DD-WRT First Install

With the router now running the DD-WRT software and a IP address in the same range, we just need to connect to the router and do a couple more things; change the default password and perform a reboot. This is important to do after flashing.

  1. Open your browser at You should now see the cool new DD-WRT interface. This is the new address of you router.
  2. The first thing you’ll be asked to do is change the default username and password. You must enter a new username and password here (you’ll have to confirm the password). It’s important you remember what you enter here, as you’ll need it every time you enter the access the firmware.
  3. Now you’ll get the main DD-WRT interface. But before we play around, we need to reboot the router after flashing the firmware. Click on the “Administration” tab, this will bring up a new set of tabs. Now click on “Management” tab. Finally click on the “Reboot Router” button at the bottom and wait 30 or so seconds for the reboot to finish.

Congratulations! You should now have a far more powerful and stable Linux based DD-WRT router.