Thursday, January 26, 2012

How To Extend Your Wireless Network with Tomato-Powered Routers


2012-01-24_140209
If you’re underwhelmed by the reach of your wireless signal, follow along as we show you how to extend your wireless network using routers powered with Tomato firmware.
Last year we showed you how to extend your network using DD-WRT powered routers. Since then, several readers have written in, asking how they could do the same thing with Tomato routers. Many of them said they’d switch to DD-WRT if they had to, but would prefer to keep using Tomato if possible. Although Tomato doesn’t have a perfectly analogous match to the DD-WRT repeater mode (more on this later) you can easily link two Tomato routers together with only a few minutes of configuration.

What You’ll Need

For this tutorial the requirements are quite minimal. You’ll need the following things:
That’s it! You technically don’t even need the Ethernet cable but we always prefer to do any heavy router tweaking over a wired line (saves you the hassle of having to plug yourself in anyway should something go wrong with the wireless configuration and you lose you Wi-Fi connection to the router).
We won’t be covering the installation of Tomato in this guide (for that you can check out our previous installation guide to get up to speed).
A final note before we proceed. The prior DD-WRT guide we shared with you focuses on using the second DD-WRT powered router as a Wi-Fi repeater. Currently, Tomato (and it’s derivative TomatoUSB) do not include the specific software components necessary for a true Wi-Fi repeating mode. The network extension tool included in Tomato is known as Wireless Distribution System (WDS). If you’re interested in the technical aspects of WDS you can check out this Wikipedia entry here. For our purposes there are only a few key details we need to highlight.
The most important difference between setting up a pure repeater (as per our DD-WRT guide) and setting up a WDS node, is that the WDS suffers a performance hit after the first transmission hop. What this means in practical terms is that if you were, say, transferring a file between a laptop in your bedroom which was connected to your WDS node upstairs (which is then, in turn, connected to your actual router in your office), and then to a network drive connected to that office router, you’d suffer a theoretical performance hit of 1/2 the Wi-Fi transmission speed.
This sounds like an awful compromise, but in reality you likely won’t even notice it. Unless you’re trying to transfer massive files over your network by Wi-Fi (which isn’t very practical to begin with) the potential halving of transmission speed is of no practical impact for simple web browsing and small file transfers–and is far outweighed by the huge signal boost you get from the placement of the secondary node.
Although we’re focused on extending a Wi-Fi network with this guide, it is worth noting that you can use the secondary router (once configured in WDS mode) to plug in wired devices via Ethernet. Thus you could, for example, place the secondary Wi-Fi router near a network-enabled printer or older computer without a Wi-Fi connection and use the secondary router as a sort of Wi-Fi Ethernet bridge.
All that said, if  you find the Wi-Fi performance hit to be unacceptable you can always flash your secondary node with DD-WRT and configure it as a pure repeater.

Getting Started Configuring Your Primary Router and Node

To cut down on confusion we will, henceforth, refer to the router that your internet connection is hooked up to as your Primary Router and the router you’re configuring to be your network extender as your Node. It is very easy to accidentally apply settings to the wrong administrative interface so, despite the relative simplicity of the following instructions, it’s critically important that you make sure you’re applying the settings to the correct side of the equation. Always double check if you’re supposed to be working with the Primary Router or Node.
The following instructions start from the premise that you have two routers, both with Tomato installed, and both plugged in.

First, navigate to the administrative interface of the Node. This is where it is extremely helpful to use the Ethernet cable as, even if the default settings on the Node confliction with the default settings on the Primary Router, your direct wired connection will overrule that.
In the administration panel of the Node, navigate to Administration –> Admin Access –> Color Scheme. Select an alternative color scheme for the Node. The default color scheme for Tomato is, simply, “Tomato”. We changed the color on the Node to “Blue”. It seems trivial but you’re going to spend the next 20 minutes plugging in commands to the two interfaces and something as simple as a different color scheme will decrease the chances you plug in the wrong parameters. Also, for future tweaking, it’ll make it immediately clear which of the devices you’ve logged into. Now would also be a great time to scroll down in that same Admin Access sub-menu and change the access password on the router if you haven’t done so already. Make sure to click Save at the bottom to save your changes.
After you’ve set the color and changed the default password to something more secure, it’s time to begin configuring the Node to serve as a WDS access point. Navigate to Basic –> Network on the Node. We have quite a few settings to toggle in this section, you may wish to print a basic check list so you can check them off as we go (trust us, it’s really frustrating to waste time trouble shooting a network problem only to find out that you forgot to change a 1 to a 2 or something as equally tiny).

Within the Network sub-menu of the Node, you want to work down through the following settings, toggling them as you go. First, toggle the WAN / Internet to Disabled. Second, change the values in the LAN section to the following:
  • Router IP Address: 192.168.1.2 (presumes your Primary Router IP is 192.168.1.1)
  • Subnet Mask: 255.255.255.0
  • Default Gateway: 192.168.1.1 (the IP of your Primary Router)
  • Static DNS: 191.168.1.1. (You may use either your Primary Router IP or your ISP’s DNS server IPs)
  • DCHP Server: Unchecked.

In the Wireless section of the Network sub-menu of the Node, configure the following settings:
  • Enable Wireless: Checked.
  • Wireless Mode: Access Point + WDS
  • Wireless Network Mode: G Only
  • SSID: The SSID of your Primary Router, i.e. linksys or wireless.
  • Broadcast: Checked.
  • Channel: The channel of your Primary Router, i.e. 6 – 2.437.
  • Security: WPA Personal (this is the strongest method you can use with WDS)
  • Encryption: AES
  • Shared Key: Enter the Wi-Fi key used by the security settings on your Primary Router.
  • Group Key Renewal: 3600
  • WDS: Link With…
  • MAC Address: In the first slot, insert the Wi-Fi MAC address of your Primary Router.
Make sure to click Save at the bottom to lock in all the changes you just made.

Now it’s time to go into the administrative panel of the Primary Router and finish the connection. Login and navigate to Basic –> Network (just like you did on the Node). In order to cut down on confusion (and the chances of you messing up the already functional configuration of your Primary Router) we’re only going to include the WDS specific changes you need to make. Scroll down in Network to the Wireless section. Toggle the following settings:
  • Wireless Mode: Access Point + WDS
  • Wireless Network Mode: G Only
  • WDS: Link With…
  • MAC Address: In the first slot, insert the WI-FI MAC address of your Node.
Note: If you weren’t using WPA Personal/AES and inserted new values for your security/encryption into the Node during the previous step, you need to make sure those settings are mirrored on the Primary Router. Click Save.
At this point, having saved the changed on both the Primary Router and the Node, you should be in business. Plug in the Node at the edge of your current wireless signal (say, upstairs or across your house) and enjoy a much stronger Wi-Fi signal.