DD-WRT: Setting up a home Wireless Distribution System (WDS)
Posted on 15 Apr ’07 by Earl Moore
I’ve been a fan of the DD-WRT router firmware for some time. I’ve even done a couple of post about installing and upgrading a Linksys WRT54G with DD-WRT firmware. DD-WRT firmware runs on a number of wireless Linux based routers and provides capabilities far beyond factory firmware, such as VOIP, VPN and advanced traffic control.
Our home is single level with a fairly long floor plan from end-to-end. My office, where the main wireless router (Linksys WRT54G) resides, is in one end of the house and there is a brick chimney between it and the main living area and kitchen. As such the wireless signal strength at the other end of the house, is often weak.
Here’s a rough draft of our home’s floor plan. It’s absolutely NOT to scale and doesn’t show all areas. You will see on this diagram the location of the primary AP (A) and of the second AP (B) that I added as a WDS node. More on that follows below.
I’d picked up a Linksys WRT54GS wireless router on Ebay some time ago and had put it away as a spare if anything should happen with my main router.
This weekend I decided to use it to set up a Wireless Distribution System (WDS) in my home to fuller home wireless coverage. Plus, I love doing projects like this!
First things first, by definition a WDS is a system that enables the interconnection of access points wirelessly. It allows a wireless network to be expanded using multiple access points without the need for a wired backbone to link them, as is traditionally required. WDS may also be referred to as repeater mode because it appears to bridge and accept wireless clients at the same time (unlike traditional bridging). It should be noted, however, that throughput in this method is inversely proportional to the number of “hops”, as all traffic uses the same channel. For example, client traffic going through one relay station before it reaches the main access point will see at most half the maximum throughput that a directly connected client would experience.
If you have two wireless routers with the DD-WRT firmware installed it’s simple setting up a WDS. I chose to set up a LAN-type WDS, although the options also allow you to set up a point-to-point WDS. A LAN type WDS is the easiest and most common as it requires no extra routing protocols or knowledge of networking, it is simply network bridging.
Below are the steps for setting up the WDS:
1. First you should make sure you’re using the same wireless settings on both routers and initially not any type of Wireless Security. If you have WEP or WPA security currently setup, disable it for the time being. You should also have the ability to access the web interface for each router. This access should not be via a wireless link but by an ethernet link.
2. On your main router, in my case the WRT54G (A), navigate to the Wireless/WDS section, select any row that says “Disable” and change it to “LAN” then enter the wireless MAC Address of the other router (B) on the row you changed to “LAN”.
Note: I’ve blurred out the MAC Addresses and some IP Addresses for security reasons.
3. On your secondary router, in my case WRT54GS (B), navigate to the Wireless/WDS section, select any row that says “Disable” and change it to “LAN” then enter the wireless MAC Address of the main router (A) on the row you changed to “LAN”.
Steps 2 & 3 tie the two routers together into one LAN.
Make sure you typed these MAC Address numbers correctly then save your settings.
4. Go to the Wireless Status Page of each router. You should see WDS Link and the Wireless MAC of the other router listed, with a signal reading. If the signal is “0dBm” then there may be something wrong. Check your antenna connections and configuration settings, and try again.
5. Once you have a decent signal, you can change the Internet Connection Type on the Basic Setup page of the second router to Disabled and set the Gateway to the LAN IP Address of the first router. This will route all traffic to your main wireless router/AP (A).
My secondary router/AP is IP Address 192.168.1.2 while my main router/AP is 192.168.1.1. Since I also use DHCP to assign IP Addresses on my home network I set the DHCP Type on my secondary router/AP (B) to “DHCP Forwarder” which will forward all request for IP Addresses to my main router. I entered the IP Address of my main router (A), 192.168.1.1, as the DHCP Server.
6. You can now run normal test to check if you are connected (ping).
7. Once you are sure you are connected and that everything is working, then you can set up Security. It is strongly recommended to use WPA Pre-shared Key with AES and TKIP as it is secure and easy.
You should not use WEP security with WPS!
This project was a fun and successful. I now have great wireless coverage over my whole home. If you already have a Linksys or other supported wireless router this project is very inexpensive. You can get a second router for about $40-50 USD. Also the DD-WRT v23 SP2 firmware is free.
I’ve listed a number of related resources below.
DD-WRT Firmware: V23 SP2 Update – Blog Post – Dec. 2006
DD-WRT Firmware: v23 SP1 update – Blog Post – Jul. 2006
LinkSys WRT54G Firmware DD-WRT Upgrade – Blog Post – Mar. 2006
DD-WRT Home site – dd-wrt home web site
DD-WRT Download – dd-wrt download web page
List of Routers Supported by DD-WRT – Blog Post