How do I create a secure home wireless network using a Linksys DSL/Cable router?

 

As more people convert their existing home networks to wireless the need to make sure that your network is secure has become even more important.  This issue is even more critical to NIL because of PHI that may exist on our computers. 

 

In order to protect your computer network, the CSG highly recommends that all home broadband users, with intentions of setting up a wireless network, purchase a Wireless Linksys DSL/Cable Router (WRT54G is the most basic model).  These routers include 4 network ports for wired connections and allow the use of up to 254 wireless devices on your network. 

 

The procedure for installing the Linksys router will differ depending on whether your DSL/Cable modem installation uses PPPoE. Point to Point Protocol over Ethernet (PPPoE) is an extension of the original PPP protocol used for dialup connections. PPPoE requires that the DSL or Cable modem user initiate the connection by providing a username and password. Older DSL and Cable modem connections do not use this method. In the procedure below, certain steps will only apply to PPPoE users.

 

Installing the Linksys Router

 

Follow these steps to install your Linksys Wireless router

 

1. Be sure that the DSL or Cable line is functioning.

Connect your computer to the DSL or Cable modem using the manufacturers instructions. Test the connectivity and be sure that DSL or Cable line is working correctly before you install the router. If you are not using PPPoE, setermine if you IP address is dynamic (DHCP) or static (permanently assigned to you and manually entered). If it is static, be sure to note the IP address settings given to by the DSL/Cable provider. If you are using PPPoE, be sure to note the username and password that are used to initate the connection.

2. Connect your router to your home network.

Turn off your computer and unplug the network line from the DSL or cable modem. Plug the line from the DSL or Cable modem into the WAN port on the back of the DSL router. Use another network line to connect the network port on the computer with one of the numbered network ports on the back of the router.  You may also configure a wireless network without physically plugging a computer in, but it is a good idea to plug a computer into the router directly for configuration.  This will allow you  to still connect to your router in case the security settings prevent a wireless connection.

3. Configure the computer to obtain an IP Address from the router.

Turn on the router, cable modem, and the computer. Make sure that your computer is configured to obtain an IP address automatically. You should also be sure to disable any PPPoE software that was installed on your computer.

For a Macintosh, you will need to go to the Apple menu, Control Panels, TCPIP. Make sure that TCP/IP is connected to the Ethernet port and that it is set to use a DHCP server as shown below:

For a PC, you will need to go to the Start menu, Settings, Control Panel, then double click on Network. Click on the Protocols tab in Windows NT. When you see TCP/IP, click on it, then click on Properties. Change the setting to "Obtain an IP Address Automatically" and click OK as shown below.

 

4. Configure the router for your Cable/DSL provider

You may connect to your router configuration page via any web browser.  The address to connect to for Linksys routers is 192.168.1.1.  By default the username field is blank and the password is “admin”.   Your configuration page will look similar to the following image.  Some models will vary slightly.

On the line that says connection type make sure it is set to DHCP for cable internet access and to PPPoE for DSL internet access.  When you change the connection type to PPPoE it will prompt you for a username and password.  This is where you will enter your username and password provided to you from your DSL provider.  Once the proper connection type is verified click on the STATUS tab.  Your browser will look similar to the following image.  Be sure that the IP address and default gateway fields are populated.  If you have zeros in these fields unplug your cable/DSL modem and your router and then power the modem back up.  Once the modem is connected power the router back on. 

 

At this point your router has an internet connection.  We will now configure the security for the wireless network.

5. Configure wireless security settings

At this point the router is configured and your network should be fully functional as a non-secure wireless network.  On your router configuration page find the section that pertains to Wireless Security.  This will be either on the Main Setup page or under a sub-header titled Wireless.  You should see a section similar to the following screenshot:

If you plan on using both Wirless A and Wireless G access be sure to leave the Mode on Mixed.  If you are strictly using Wireless G change it to Wireless G only.  If you are unsure just leave it on Mixed Mode.  The channel will only change if you are trying to chain together multiple networks.  If you are not doing this just leave the default setting.  Be sure to change the SSID to something other than the default.  Most hackers are familiar with default network names.  Be sure to Enable WEP settings.  This is the security protocol most commonly used with Wireless networks.  WPA security is also available, but not all devices are WPA equipped.  After you enable WEP click on Edit WEP Settings.  You will have a window similar to the following:

Select 128 bit encryption and enter a passphrase, this can be any word or phrase that you choose.  Click on Generate and a series of keys will be generated.  It is a good idea to save these keys to a text document that is in a safe spot.  This will make it easier to add machines to your wireless network in the future.   Click on Apply and your security will be setup.  At this point your router is configured for your wired and wireless networks. 

 

Configure wireless computer to connect to your network.

On your laptop or wireless desktop look for the wireless internet icon in your bottom right hand corner, by the clock.  Right click on the icon and select View Wireless Networks.  This can also be access by clicking on Network Connections in the control panel.

You will then see a screen similar to the following:

 

Your network will be listed with the SSID name that you assigned.  It should be listed as a Security-enabled wireless network.  Click on connect and you will be prompted to enter your wireless access key.

The easiest way to enter this is to copy it and paste it from the text file you created earlier with all of your keys on it.  You can use any of the keys that were generated to connect.  Enter your key and click connect.  At this point you are connected to the wireless network and you should be able to open web pages and perform other internet based functions.  Once you know that everything is connected click on Advanced Settings.

 

You will see the following window:

Click on Wireless Networks.  If you would like to make sure that your notebook only connects to your network you may remove any other networks from the list.  Click on the properties button, the properties dialogue box should look like the following:

 

Your Linksys wireless  router should now be installed and functional. All internet programs, such as web browsers and email clients so be able to transparently use the router. Certain programs such as games and X-Windows programs will need special configuration to use the Linksys router. For more information you can read the FAQ How do I run X-Window applications using a Linksys DSL/Cable Router? , or refer to the Linksys documentation at http://www.linksys.com/support/support.asp?spid=1.