Advanced wireless home networks are becoming much more widespread—especially those being installed by non-networking professionals. With that said, manufacturers of home networking equipment don’t seem to get it yet—people want features! More than that, home users want to do many of the the things the big-wig networking professionals are doing in their enterprise networks. This article will cover one of the more simplistic features that router manufacturers seem to overlook—using a wireless router as a wireless bridge.  I suppose you could ask, “why not just go out and by a bridge?”  That would have been the more logical response in the early days of wireless home routing, but now the costs of wireless routers are not much more than that of a bridge.  If the price isn’t much more, why not get all of the features of the router as well?  You may decide to re-purpose your router (serving as a bridge) as a full-fledged router at a later date. As of this writing the WRT310N Wireless-N (802.11n) router can be purchased for around $110.  There have been efforts to make router operating systems open-source and many routers can be flashed with these alternative operating systems.  This is what we will be doing with the WRT310N as it does not have native support for bridging. 

Technically, what will be doing is creating a bridge that is referred to as a  client bridge/AP (Access Point), because we will join our wireless routers under the same network segment.  Standard bridging joins two different networks using different subnets. An example of a real life scenarios where you might use a client bridge is as follows:

You have a wireless home network in the basement of your home, but you’d like to have access to your home network in an upstairs office.  Your two office PCs do not have wireless LAN adaptors—only standard RJ45 ethernet connectors.  The solution is to place a wireless router (in our case a WRT310N) in the office re-flash its memory, configure, and connect the PCs to the router via ethernet cables.

The software package we will be flashing the router with was created by NewMedia-NET GmbH and is located in the download section of the DD-WRT Web site. DD-WRT is one of the most predominant 3rd party router software makers and provides it for free under a GPL license.  On top of the added bridging features, the DD-WRT router software gives nearly full access to all of the router’s (more specifically, the Broadcom chip) services and monitoring capabilities. For instance, after the load you will be able to monitor the router load (1/5/15 minute), monitor throughput, utilize RADIUS, view routing errors, view tx/rx errors and export rflow data. 

Now down to business, here are the steps to configure your WRT310N as a winless client bridge/AP:

IMPORTANT:  This is a “do-it-at-your-own-risk” project.  While none of these steps will damage any physical hardware, you may loose settings, lose network connectivity, or “brick” your router (i.e. lock it up so that it will not route or allow an administrative login).  If the flash process does cause the router to be “bricked” you can restart the process all over again. Follow the recovery procedures at the DD-WRT Web site.

NOTE: you should not have to change ANY settings on your existing wireless router.  In this configuration, the WRT310N is a NEW, additional, router to your network. The routers should have compatible 802.11a/b/g/n protocols as well. In the case of the WRT310N, it is a Wireless-N router, so it should be backwards compatible with older protocols such as 802.11/b/g.

1—Make sure your PC is plugged into any of the non-WAN (Internet) ports of the WRT310N router

2—Log into your router (the factory default URL to the router is http://192.168.1.1, if you have changed the IP then enter this instead)

NOTE—If you are re-purposing the router get any important settings you might need (i.e. IP address, wireless security settings etc..)

3—Factory reset the router in the (menu->Administration->Factory Defaults->Restore All Settings)

NOTE—The default user and password of: admin / admin will now be set on the router

4—Hard Boot the Router (Depress reset button down in back for 10 seconds and pull the power plug without releasing the reset button)

5—Download the mini version (dd-wrt.v24_mini_wrt310n.bin ) of the DD-WRT software for the WRT310N router (the mini version is scaled down for the easiest/safest installation)

6—Flash the WRT310N router with the DD-WRT binary you just downloaded (menu->Administration->Firmware Upgrade)

7—After a successful flash, factory reset the router in the (menu->Administration->Factory Defaults->Restore All Settings)

8—Hard Boot the Router (Depress reset button down in back for 10 seconds and pull the power plug without releasing the reset button)

9—-Log into your router (the default URL to the router is http://192.168.1.1)

Note:  You will now notice a new look to the router software, as you are running DD-WRT

10—Change the login name and password—write it down!

11—If all is going well so far, then we can upgrade the DD-WRT from the mini version to the standard version. Download the standard version (dd-wrt.v24_std_generic.bin) and follow steps 6-10 using the standard version binary of DD-WRT.

12—Now it’s time to configure the new router as a client bridge.  Log into the router and click on the “setup” tab.

13—Under setup->Local IP Address,  I suggest setting the router to your existing IP plus one (assuming your existing is set to the factory default of 192.168.1.1 —set the the new router to 192.168.1.2).  It must remain within the same subnet as your primary router. 

14—Assuming you use the values in step 13, your subnet would be 255.255.255.0

15—Both the “Gateway” and “LocalDNS” will be the same as your primary router (following with step 13 and 14 both IPs would be: 192.168.1.1)

16—Click Save

17—Click Apply

18—You will now have to log into the router with the new IP you assigned. (following with steps 13-15, the URL would be: http://192.168.1.2)

19—Go to the Wireless tab and set the “Wireless Mode” field to “Client Bridge”

20—Set the “Wireless Network Name (SSID)” to exactly the same SSID that your primary router has

21—Set “Network Configuration” to “bridged”

22—As this is a layer 2 bridge, you must set your wireless security settings to be exactly the same as your primary router (for example if you are using WPA2 Personal—set the mode, key, and algorithm to be the same on both routers 

23—Click the status->wireless->”site survey” button.  This will show all of the wireless networks within range.  Find your primary router and click the associated “join” button.

24—Click Save

25—Click Apply

26—For good measure, lets power-cycle the primary router (unplug and wait 10 seconds, plug back in)

27—Power-cycle the WRT310N bridge/router (unplug and wait 10 seconds, plug back in)

That’s it, now plug in your wired ethernet devices to the WRT310N and you should now be connected to your home network.

*** NOTE: if any of the router flashing procedures fail and you cannot log back into the router, follow the flash recovery procedure detailed on the DD-WRT Web site. ***