HowTo: Connect Two Wireless Router Wirelessly ( Bridge ) With Open Source Software

by on August 31, 2012 · 14 comments· LAST UPDATED October 2, 2012

in Networking, Open Source

You can setup a wireless connection between two routers only so that it will link a wireless network to a wired network allowing you to bridge two networks with different infrastructure. You can find wireless access points products that offer either a "bridge" mode or a "repeater" mode. In this post I'm going to explain three popular open source choices that can be used for setting up a wireless bridge.

Sample setup

Consider the following network diagram:

Fig.01: Wireless client setup

Fig.01: Wireless client setup

  • You connect to the Internet using standalone ADSL2 modem with 202.54.1.1 public IP address.
  • SSID set to nixcraft on wireless # 1 and an IP address set to 192.168.1.2. This router is located in downstairs and connected to ADSL2 modem.
  • SSID set to nixcraft on wireless # 2 and an IP address set to 192.168.1.1. This router works in client bridge mode and located in upstairs.
  • All computers and devices connected to wireless router #1 and #2 can share files and other resources with each other.

Fig.02: Access point as a wireless bridge

Fig.02: Access point as a wireless bridge


Where,

  • This setup saves electricity and resources by removing standalone ADSL 2 modem.
  • You connect to the Internet using combo ADSL2 modem plus wireless router (AP) with 202.54.1.1 public IP address. This router is called wireless #1 and SSID is set to nixcraft. This device has two IP address and it is located in downstairs.
  • SSID set to nixcraft on wireless # 2 and an IP address set to 192.168.1.1. This router works in client bridge mode and located in upstairs.
  • All computers and devices connected to wireless router #1 and #2 can share files and other resources with each other.

Software (3rd party firmware)

You can use the following software / firemware to get the addition features which are not typically included in a manufacturer's router firmware such as client mode wireless bridge. You can either setup a full WAP or just bridge your LAN so that wireless devices can get access to all LAN resources transparently.

  1. DD-WRT : Linux-based alternative OpenSource firmware for wireless routers. It works for several routers, most notably the Linksys. It works great with variety of wireless routers and embedded systems. This is recommend for new users as it comes with easy to use web-gui.
  2. Tomato : Another simple and easy to use replacement firmware for Linksys' WRT54G/GL/GS, Buffalo WHR-G54S/WHR-HP-G54, Asus and other Broadcom-based routers. It features a new easy to use GUI, a new bandwidth usage monitor, more advanced QOS and access restrictions, enables new wireless features such as WDS and wireless client modes, raises the limits on maximum connections for P2P, allows you to run your custom scripts or telnet/ssh in and do all sorts of things like re-program the SES/AOSS button, adds wireless site survey to see your wifi neighbors, and more. This is recommend for new users as it comes with easy to use web-gui.
  3. OpenWrt : OpenWrt is not just firmware but it is often described as a complete Linux distribution for embedded devices. Instead of trying to create a single, static firmware, OpenWrt provides a fully writable filesystem with package management. This frees you from the application selection and configuration provided by the vendor and allows you to customize the device through the use of packages to suit any application. This firmware is recommend for advanced users only.
  4. DIY option - You can install Linux or FreeBSD/OpenBSD based operating systems and create a full WAP or just a bridge. This option requires good understanding of Unix, networks and embedded devices.

I strongly recommend DD-wrt for new users and openwrt for advanced Linux users.

Hardware

I've used the following devices in last couple of years for personal usage:

  1. Linksys WRT 54 with DD-WRT firmware.
  2. Dlink DIR-615 with DD-WRT firmware.
  3. Asus RT 16 with Tomato firmware.
  4. Soekris net4801 with DIY option. You can use Debian/Ubuntu/CentOS Linux and FreeBSD/OpeNBSD. This option is only recommended for advanced hardcore unix users.

You can find list of supported router hardware by visiting the following pages:

Example: Configuring Asus RT-16 as a wireless bridge

Let us see how to configure a wireless connection between two routers only as discussed earlier with tomato firmware.

Wireless # 1: ADSL2+router configuration

This is my ADSL 2 modem + wireless router (netgear N600) that connects to my ISP. This is my primary router and it is called wireless #1. Open a browser and type:
http://192.168.1.2
Make sure LAN setup is as follows:

Fig.03: Netgear N600 (DGND3700) Static Lan IP Configuration For Wireless Bridge

Fig.03: Netgear N600 (DGND3700) Static Lan IP Configuration For Wireless Bridge

  1. Set the IP address of your router in dotted decimal notation to 192.168.1.2 (factory default: 192.168.0.1).
  2. Also set IP subnet mask to 255.255.255.0. Your router will automatically calculate the subnet mask based on the IP address that you assign. Unless you are implementing subnetting, use 255.255.255.0 as the subnet mask (computed by the router).

Setup wireless as follows:

Fig.02: Prepare Netgear N600 / DGND3700 For Wireless Client Bridge Mode

Fig.04: Prepare Netgear N600 / DGND3700 For Wireless Client Bridge Mode

  1. Set SSID to nixcraft.
  2. Setup mode as per your requirements. I set it to 300Mbps performance mode, with a maximum Wireless-N speed.
  3. Set security options to WPA2-PSK standard encryption with the AES encryption type.
  4. Finally, set the WPA passphrase (network key) as per your requirements. For demonstration purpose I set it to "Neil_Armstrong".

Wireless # 2: Router client bridge configuration

I'm assuming that you've already replaced your default firmware with DD-WRT/Tomato/Open-WRT. In this example, I'm going to use tomato firmware.

How do I use Tomato firmware as wireless ethernet bridge?

Fire a web browser and type the following url:
http://192.168.1.1
Click on Basic > Networking. Make sure LAN is setup as follows:

Fig.05: Totmato USB firmware LAN setup for wireless bridge

Fig.05: Totmato USB firmware LAN setup for wireless bridge

  1. Make sure router IP address is set to 192.168.1.1.
  2. Make sure subnet is set to 255.255.255.0.
  3. Make sure default gateway is set to 192.168.1.2 (IP address of wireless # 1).
  4. Make sure static DNS is set to 192.168.1.2 (IP address of wireless # 1). However, you can set it to OpenDNS or Google DNS.

Scroll down to the Wireless section and set it as follows:

Fig.06: Tomato wireless settings for br0

Fig.06: Tomato wireless settings for br0

  1. Set wireless mode to "Wireless Ethernet Bridge".
  2. Set wireless network mode to "N only" or as per your requirements.
  3. set SSID to "nixcraft".
  4. Set security to "WPA-2 Personal" and encryption to "TKIP/AES".
  5. Set shared key to WPA passphrase (see Fig.04: Prepare Netgear N600 / DGND3700 For Wireless Client Bridge Mode). In this example set it to "Neil_Armstrong".

Click on Advanced > Routing:

Fig.07: Setup tomato in gateway mode

Fig.07: Setup tomato in gateway mode

  1. Set mode to "Gateway"
  2. Make sure RIP1 & v2 set in "Disabled" mode.
  3. Turn on "DHCP routes" for dhcp relays i.e. send all dhcp requests to DHCP server located at 192.168.1.2 (or any other server on LAN)

Click on Advanced > Firewall. Set it as follows:

Fig.08: Firewall settings for br0

Fig.08: Firewall settings for br0


You are done. Configure any other settings you wish at this point. To see current router status click on Status > Overview:
Fig.09: Tomato status page - running in a bridge mode

Fig.09: Tomato status page - running in a bridge mode

Have any advice for better 3rd party firmware or software? Let's hear them in the comments.

TwitterFacebookGoogle+PDF versionFound an error/typo on this page? Help us!

  • Joe Cruz

    I have a similar setup at home. I use a stock Linksys E2500 as the main Router because of the simultaneous dual band capability. I have a Linksys E2000 running Tomato Toastman’s build on 5ghz band for my home theater so that I can provide wired ethernet to a Roku and a Blue Ray player. I also have a Linksys WRT160N v1 also running Tomato Toastman’s build to provide wired ethernet to my home office. This allows for watching video on 5ghz without any interference to the data network running on 2.4ghz.

  • Rick

    I think you have two typos. Figure 03 looks good, but right under it Step 1, I believe should be 192.168.1.2 and Step 2, you have 25 instead of 255 for the first part of the subnet mask.

  • Manoj.V.Nair

    Hi
    I have a doubt that is it possible to use different range of ip address on both routers so that internal routing can be possible?
    Also if the Name resolution can be possible in virtual NICs, then is there any place for router?

  • http://www.cyberciti.biz/tips/about-us Vivek Gite

    Thanks for the heads up!

  • Jose

    So, i followed the steps and I think I did it ok, but I don’t know how to see which router I am connected to… How can I check if I did everything ok?

  • Matthew Moldvan

    In figure 6, setting Wireless Mode to “Wireless Ethernet Bridge” and Wireless Network Mode to “N Only” doesn’t work. Wireless Network Mode has to be set to Auto when it’s in wireless client mode… I see in your last figure that it’s set that way.

  • vikram sharma, kolkata

    i have a n300 dlink cloud router on my first floor and tplink n150 repeater on my ground floor. it used to work fine when i had a netgear n150 router on my first floor. I have checked the configuration also it is ok. Now if I put a lan switcher and use both wifi router as separately will it work?

  • Ben

    Hi,
    Thanks very clear.
    One question: is it possible to have a different WPA key to access to wireless#2 from wireless#1 ?

  • YT KO

    but seriously… why would you call router #1 192.168.1.2 and router #2 192.168.1.1 ?

  • bnhsdad

    Taking your first picture shown, can this “network” be created without the modem/internet connection? My situation is that I have timing equipment (for timing running races) that I currently connect back to the main computer by ethernet. I do not connect to the internet for timing the races. I’d like to find the equipment to be able to connect them by a wifi set up (with external antennas) so I can put the remote devices a bit further away and also not have to worry about someone snagging the cable and losing the connection.
    The only other issue is that currently, when I connect to those devices, they are identified by an IP address not by a MAC address. The ideal situation would be to make the router to router connection and then have it appear to the computer as if it were an ethernet cable connected to the timing machine.
    Someone on the Linksys support forum said that the WRT54GL would not work for this, I would need an “enterprise intranet bridge”.

  • Brad Gibbons

    Does anyone know of a third-party firmware option that I could install on my 2wire HomePortal 1700HW to allow me to use it as a wireless repeater? I simply want to extend the range of a preexisting Wifi network without having to hook up the 2wire to DSL or to any other device. Unfortunately it is not supported by any of the three systems discussed in this article, and I lack the knowledge for the “DIY” option of installing a full linux/BSD OS.

  • paul_krupa

    Yeah! I was wondering that too.

  • k2water

    would be careful when using DD-WRT as during the installation for my Netgear it decided to brick and ruin my 70$ router, Words cannot describe how utterly pissed i am for trying to help my family with internet access just to watch the installation bar stop and then the lights on my router flicker over and over with no way to reset to factory default or restart it to an earlier backup of the router.

  • gary

    And, if we are bridging, shouldn’t it be to another subnet, like 192.168.2? I don’t know if I should try this. Because, the example is in the same subnet… why bridge this? I have a hotspot on 192.168.1 and my local wireless router is on 192.168.2 with no internet access at the moment. If I do this entire process with DD-WRT on my local router (192.168.2) can I specify a gateway of 192.168.1.1 and have it find my hotspot?

Previous post:

Next post: