Beyond the WRT54G: DD-WRT for Many Flavors of Hardware

By Aaron Weiss

May 27, 2008

When we write about DD-WRT firmware, we usually mention the Linksys WRT54G router in the same sentence. But, the truth is, DD-WRT can also work well with many other routers--and even PCs.

When you read about the DD-WRT firmware, you usually also hear about the Linksys WRT54G mentioned in the same sentence, and vice versa. The combo is like an old married couple, seemingly together everywhere they go. Indeed, we've talked about the two often right here. But the truth is, DD-WRT has had a little something going on the side for awhile. DD-WRT can mate with routers besides the WRT54G series. A lot of other routers. In fact, it really gets around.

If you want to enjoy the benefits of DD-WRT's comprehensive feature set, from building wireless bridges to repeaters to hotspot management and prioritizing gaming performance, you needn't be wed to Linksys routers (not that there's anything wrong with that.) There's a whole world of wireless routers out there that will hit it off with DD-WRT.

Chipsets, memory, and flashing

If you're familiar with DD-WRT, then you already know that it is an open-source firmware designed to replace the stock software loaded by the vendor with a much-improved feature set. DD-WRT isn't the only one of its breed—there are OpenWRT and Tomato, for example—but it is probably the most popular. (We don't have hard numbers to prove this because Billboard refuses to include router downloads on the Hot 100 charts.)

There are dozens of vendors who sell wireless routers. Usually you will find the big name brands in brick and mortar stores—Linksys, Netgear, and D-Link. Online retailers often carry many more, such as Asus, Belkin, and Gateway.

The fastest way to determine which routers you can load DD-WRT on is to check the list of supported devices at DD-WRT's wiki page. This chart is an essential resource, but it can take some guidance to make sense of.

In reality, many consumer-grade wireless routers are built around basically the same core hardware, just like most PC's are built around a handful of processors. In PC land, the two major processor vendors are Intel and AMD. In wireless router-ville, the names you need to know are Broadcom and Atheros. With few exceptions, most wireless routers use either Broadcom or Atheros chipsets for their "brains."

DD-WRT was originally developed for the Broadcom chipset used in the original Linksys WRT54G router, and so naturally, it continues to support Broadcom-based routers most strongly. The good news is, there are a lot of them.

Of course, the Linksys WRT54G router is the one that started it all, but note that versions 4 and older of this router are the most compatible with DD-WRT. Newer versions of the router can work with DD-WRT, but loading it is more complicated. Also note that V7 of the WRT54G cannot work at all with DD-WRT. Alternatively, Linksys now sells the WRT54GL, all versions of which are known to work with DD-WRT.

Although many vendors now make DD-WRT compatible routers, the price-performance king is considered to be the Buffalo WHR G54S. However, a (possibly temporary) court injunction now prevents Buffalo from selling direct to the U.S. market. American buyers can still find the Buffalo router from overseas e-tailers and on eBay, generally for under $50.

Only in the newest DD-WRT release--V24--has the software introduced appreciable support for Atheros-based routers.

Wireless routers also vary in how much flash memory they've been gifted with. Common capacities include 2, 4, and 8 MB. You cannot load the full version of DD-WRT into a router with only 2MB of flash memory. A stripped-down "micro" version of DD-WRT is available for these routers, albeit with some features removed, like hotspots and kaid server (for xbox live gaming).

Most consumer routers include 4MB of flash, which is enough to run the full DD-WRT, but will limit how much on-board storage you will have remaining for extra feature packages or embedded data, such as Web pages. A plump 8MB or greater router can load the "mega" build of DD-WRT, which throws in VPN and SIP support, plus uses onboard memory for storage of embedded data or additional packages.

Take home message: the most common and most tested routers for DD-WRT are Broadcom-based models with 4MB of flash memory.

A third consideration to take into account when reviewing the supported devices chart is the column labeled "Notes for running DD-WRT." Just as there is more than one way to do certain things to a cat, there is more than one way to load (or "flash") DD-WRT. But sometimes there is only one way that will work for a particular router model, with other methods risking death (of the router, not you, or a cat.)

The two most common methods for flashing DD-WRT onto a router are using the Web interface and using TFTP. Both the stock firmware loaded onto your router by the vendor and DD-WRT will include a Web-based administration page, which lets you flash the router with a new firmware. If the chart says "Web interface," than you can use the Web interface to do this. Some routers cannot be flashed with the Web interface, though, and may be damaged if you try, which is why it is important to consult the chart for your model.

The TFTP flashing method uses the "tiny ftp" protocol to upload the DD-WRT firmware onto the router. Some routers include a graphical TFTP client that you can use; others may require that you delve into TFTP on the command line (such as in Linux). You'll see in the chart that some routers, such as Belkin models, must be flashed using TFTP.

Besides these methods, some routers like Asus models include a vendor-supplied flashing tool that you can use, as noted in the chart.

In many cases, you may need to use the vendor-supplied flash tool or TFTP to load DD-WRT for the first time. Once DD-WRT is loaded, you may then be able to upgrade it in the future using its Web-based flashing page. For this reason, you will see many models listed with the note "initial flash," describing which method you must use the first time.

Besides Web, TFTP, and vendor utilities, some outlier models require unusual and technically complicated methods that involve hardware modification. It is probably best to avoid these routers altogether.

When reviewing the supported devices chart, also be sure to check the column "Min required DD-WRT version." Attempting to flash a router with a version of DD-WRT that is too old could render it useless.

DD-WRT unleashed

Consumer-grade wireless routers are convenient things because they are small and consume little power. But they are limited in memory capacity and processor speed. For larger scale wireless deployments, these routers will bog down or keel over under the load of dozens, or hundreds, or thousands of users.

In enterprise networking situations, from large corporations to ISP's, DD-WRT supports several commercial hardware platforms, which offer significantly bigger iron than an off-the-shelf blue box router—platforms like Avila Gateworks, Cambria, Atheros Soc, Compex, Senao, Fonera, and Ubiquiti. Special builds of DD-WRT are available for these platforms.

An alternative to big-iron-big-dollar router hardware is the good old x86 platform. In other words, your old (or new) PC. Compared to a consumer-grade router, even a decade-old PC is orders of magnitude faster and can support far more memory.

Repurposing a retired or semi-retired PC for DD-WRT use may require outfitting the PC with wireless and wired networking cards. Unlike DD-WRT for consumer routers, though, the x86 version requires purchasing an activation key to use all of its features. (This is equally true for the commercial platforms listed earlier.) License fees begin at around 19 Euros per user for ten users, and go down from there as the number of users increases.

DD-WRT for x86 can be deployed in a trial configuration. The software is distributed as a disk image and needs to be imaged onto a disk partition. Common ways to do this involve booting from a live Linux distribution like Knoppix or Damn Small Linux and then writing the DD-WRT image to a prepared partition.

Writing in shorthand

Often when we write about DD-WRT, we say something like "on a supported router like the WRT54G."

But, lest this repeated shorthand leave the wrong impression, clearly DD-WRT can be run on a wide range of wireless routers. You may already own one right now.

Aaron Weiss is a writer and Wi-Fi enthusiast living in upstate New York. He is also our Wi-Fi Guru. You can write to him by clicking on his byline above and putting "Wi-Fi Guru" in the subject line.

Originally published on .

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