Dual Band Networking Guide
Reviewed by: flareback
Reviewed on: May 15, 2008
Dual Wireless Networks
Before we begin, we should ask why you would want to set up two wireless networks. Two wireless networks will prevent you from needing to run your wireless networks in compatibility mode. Compatibility mode allows your network to support backwards versions of 802.11x. So an 802.11n (from here on referred to as 'n') network in compatibility mode, will allow users with 802.11g (or 'g') network cards to use your network. So why is this bad? Speed. If you have an 'n' network and a 'g' device connects, your 'n' device gets slowed down to 'g' speeds. So we want to avoid slow-down by running an 'n' and a 'g' network simultaneously.
What you need:
- 802.11n router capable of using 5 GHz spectrum - I'll be using an Apple Time Capsule
- 802.11g router - I'll be using a Linksys WRT54G
- Internet Modem
- At least 3 Ethernet cables
What we're going to do:
The Time Capsule has Gigabit ports and the WRT54G is 10/100, so I'll be plugging the Time Capsule into the Cable Modem and the WRT54G into the Time Capsule. Set up the Time Capsule to use "802.11n only (5 GHz)" mode and to be the DHCP server. The WRT54G will be set up to so that the "Operating Mode" will be "router", the "Wireless Network Mode" will be "G-Only" and it will not be a DHCP server.
Time Capsule Setup:
Connect the Time Capsule to the modem and your computer, as described in the included Time Capsule materials. In setting up the Time Capsule, if you're using a Windows machine, you'll need to install the Airport Utility that's on the included CD. I'm not sure about on a Mac, but I would imagine it comes with new ones. Once the utility starts, click on the "Continue" button to use the guided setup.
On the next screen we’ll select a name for the Time Capsule device (this is separate from the wireless network name) and a password to access it. Click Continue to come to the part where we select that we want to create a wireless network.
Next we choose the wireless network name and security. I recommend using security and a strong password, but it's up to you. After the name and security is whether the Time Capsule should give out IP addresses, or if something else on the network is doing that. Apple gives a fairly easy to understand explanation and anything I would say would only be redundant. Next is the type of Internet connection. This information can be obtained from your Internet Service Provider (ISP). Then you'll fill in your DNS addresses, Domain Names and DHCP Client ID (aka Default Gateway), also obtained from your ISP. Finally, we come to the confirmation screen to make sure everything we entered looks correct. If something is wrong, click "Go Back". Otherwise, click "Update". The Time Capsule will restart upon clicking the "Update" button and if everything was entered correctly, it should work. If you can't connect to the Internet but everything else seems to be working fine, try rebooting the modem and see if that helps.
When you have it up and running, be sure to go in to "Manual Setup" and under the "Wireless" tab look for "Radio Mode". This should be set to "802.11n only (5 GHz)". Be sure to use the 5 Ghz setting, as we'll run our g network on the 2.4 GHz band.
That's it for the Time Capsule part.
Now it's time to set up the 'g' part of our network. Unplug the ethernet cable that runs from your computer to the Time Capsule on the Time Capsule end and plug it into the WRT54G. Open up a web browser and type the address of the router into the URL bar (to find it go to "Start -> Run" type "cmd" without the quotes and hit enter. Type "ipconfig" without the quotes and hit enter and it will be the "Default Gateway" and look something like 192.168.1.1).
Enter the password (default is "admin") and navigate to the "Wireless" tab. Set up your "Wireless Network Mode" for "G-Only", change the network name to something unique and click "Save Settings".
Now go to the "Wireless Security" section and select the security type and set the password. Just a note - XP doesn't support WPA2 without installing a patch. Click the "Save Settings" button when done. Go back to the "Setup" tab and set the "Local IP Address" to something within the range of your Time Capsule. In my case, this was "192.168.1.10". Disable the "DHCP Server", since the Time Capsule is doing that for us and click "Save Settings". After saving you may have to log back in.
Go to the "Advanced Routing" tab and select "Router" from the "Operating Mode" and "Save Settings" again.
That should do it. You should now have dual wireless networks operating simultaneously.
Guide created by: Clay Johnson (aka flareback)