Today I installed the open source router firmware DD-WRT on a newly purchased Buffalo WHR-HP-G54 broadband router. I’m very impressed with its rich feature set and ease of installation.

Months ago a friend had recommended OpenWRT, another open source solution for low cost broadband routers, but following the old “don’t try to fix it if it ain’t broken” mantra, I had stuck with my standard NEC Aterm WR6650S WarpStar router (firmware revision 8.72) .

A few weeks ago I started having random problems connecting to the internet. When I clicked on links in the browser, either it was very slow or it returned an error or timed out on me. When I investigated I noticed that the internal log of the NEC WarpStar was full of error messages like these:

2008/08/24 18:09:29 NAT TX-ERROR List Create Error : UDP 192.168.1.102 : 31320 > 201.29.227.157 : 7701 (IP-PORT=1)
2008/08/24 18:09:29 NAT TX-ERROR List Create Error : UDP 192.168.1.102 : 31320 > 99.227.142.5 : 9205 (IP-PORT=1)

A router reset (briefly pulling the power cord) would cure it for a few hours to two days at most, but then the problem always came back. The router firmware obviously had trouble tracking which entries in its Network Address Translation (NAT) table could be discarded and the table would overflow, making connections to the outside world hit and miss, as NAT entries are essential for replies to requests sent to servers out there to get back into the LAN.

Of the 8 PCs and Macs in my home and office that are sharing a cable internet connection, at least four are on all the time, crunching spam data received from around the world day and night. So you can imagine that whatever router I’m using is always getting a good workout. I can’t afford it to be unreliable.

So I started doing a bit of research on OpenWRT and its cousin DD-WRT and what sort of routers that are compatible with them I could get locally here in Yokohama, Japan.

The Linksys WRT54G was the first router fitted with open source firmware, but Yamada Denki, the biggest electronics store in my part of town, does not sell any Linksys products. They were selling mostly NEC and Buffalo, but none of the models I found on the shelves appeared on the list of supported hardware.

I searched Google for the WHR-HP-G54, a supported Buffalo router, for pages in Japanese and found it on kakaku.com, a price search website. It was available for 6,500 yen from Mr. Direct, a company based in Hiroshima. Less than 48 hours later the router arrived at my doorstep by takkyubin (parcel service), for about $70 including tax and shipping.

Installing DD-WRT on the router turned out to be so easy, it actually took less time to do it than to get my Windows Vista notebook working with the new wireless security keys afterwards!

Here’s what I did:

1. First I downloaded the firmware (v24-sp1 / Consumer / Buffalo / WHR-HP-G54 / dd-wrt.v24_mini_generic.bin) and saved it on my local hard disk. Update 2009-05-25: Do not use any DD-WRT V24-sp1 builds dated in between 030309 and 051809, these builds have known problem that didn’t exist in the March 3, 2009 version and was fixed in the May 18 2009 version.
2. Next I verified the router was working with its default firmware. I hooked my notbook to one of the LAN ports by ethernet cable and accessed 192.168.11.1 with the browser. The Japanese factory firmware came up (user: root, blank password).
3. I added the tftp program in the Windows Vista control panel (Programs and Features / Turn Windows features on or off)
4. I opened two command prompt windows. In the first I executed
   ping -t 192.168.11.1

5. In the second command prompt window I went into the folder where I had saved the downloaded DD-WRT firmware and then typed the following, without hitting Enter:
   tftp -i 192.168.11.1 PUT dd-wrt.v24_mini_generic.bin

6. Unplug the power cable from the back of the router, then reconnect it.
7. As soon as you see the router responding to the PING command in the first window, hit enter on the second window (tftp command). The diag LED will flash for a number of seconds and tftp will report that the file was transferred.
8. When the LEDs on the router are quiet, the update will have finished. Renew your IP (or reboot your PC), because the router will now be at 192.168.1.1. Access it with the browser and you’re ready to configure your new DD-WRT router!