How to secure a wireless home network

MAC Filtering

Another layer of protection is to associate the MAC addresses of the computers you want to allow on your network with your router.

Every network adapter has a unique identifier called the MAC address and many routers will allow you to filter connections based on this MAC address. If a computer tries to access your wireless network and its MAC address isn't on the 'safe' list it will not be able to connect.

For each computer that will access your home network wirelessly do the following (note: this isn't required for computers that will be connected to the router via a cable): In Windows XP open up a command prompt by going to Start, Run and type 'cmd' (without quotes), and hit OK. A black window (DOS command prompt) should appear. Now type 'ipconfig /all' (without quotes) and hit Enter. If you have more that one network adapter (i.e. one for wired and one for wireless) then you'll have to determine which one is for the wireless connection. Write down the Physical Address of the network adapter.

To get the same information in Windows 95/98/ME follow the same instruction above but instead of running 'cmd', type 'winipcfg' in the Start, Run dialog box.

For example In Figure 1 ipconfig shows that there is an Ethernet adapter for the Local Area Connection (for this example let's pretend that this is the wireless adapter). The information that you're interested in is the Physical Address which in this case is 10-4D-FF-21-DC-91.

Once you have the Physical Address of each adapter that will connect to your wireless network then go back to your router settings and go to the page that deals with MAC filtering. The page will probably give you instructions on what to do but the usual method is that you will enter the MAC (Physical) address of the adapters and then check a box or setting that will allow that adapter to associate itself or connect with your network.

Figure 1: Find your Physical Address

Remove SSID Broadcast

The third layer of protection you can add to secure your wireless network is to prevent the router from broadcasting that your network exists. This means that if someone is looking for networks to connect to, yours won't show up on their list. There are programs out there that will still be able to identify that your networks exists but it will help deter casual users who aren't savvy enough to know this.

This setting is usually found in the same place where you can enable or disable the wireless network. It is usually a checkbox or drop-down that will ask if you want to broadcast the wireless network name (SSID) or not. Once you disable the broadcast then you will have to know the name of the network to be able to connect to it. It would also be a good idea at this time to write down your Wireless Network name since you'll need it to setup your computers later on.

Your Network is Secure

Keep in mind that each of these layers is not equal in terms of the protection they offer. First and foremost you should enable encryption on your router and for most people this is enough. You should be aware that more layers of protection means more time adding a new user to the wireless network, specifically the MAC Filtering. However, the combination of encryption and MAC Filtering is a strong one.