How to enable MAC address filtering on a Linksys WRT54G router

The Linksys WRT54G wireless router is capable of using many different security features, including MAC address filtering.  This article will guide you through setting up MAC address filtering on the router.

MAC address filtering can work one of two ways.  You can create a list of devices that you want to permit on your network, and any device not listed will be denied access, or you can create a list of banned devices, and as long as a device is not on that list, it will be allowed to connect to the network.

Once you've decided which method you're going to use, you'll need to get the list of MAC addresses together, whether they are the addresses to allow or exclude.  If you already have the addresses, you can skip the next paragraph.

If the devices whose MAC addresses you need are currently on your network, you can find their MAC addresses through the router.  Log in to your router's configuration software if you haven't already.  (For help with this step, see the paragraph below.)  Go to the Status tab on the far right, then beneath that click Local Network.  There will be a button labeled DHCP Clients Table; click this button and you'll see a list of all connected devices, including their MAC addresses.  If you don't know the MAC addresses that you need or how to get them, see the "Related Links" section at the end of this article for help.

When you have the MAC addresses you want to use, you are ready to set up the MAC filter.  Log in to the Linksys router software by typing the router's IP address (by default, this is 192.168.1.1) into your web browser and then entering your user name and password (if applicable).

Once you've successfully logged in, go to the Wireless tab and then beneath that, click Wireless MAC Filter.  Click the button next to Enable, and you'll see two options: "Prevent" or "Permit only."  If you want to limit certain computers from accessing your network, choose "Prevent."  If you want to allow only specified computers, choose "Permit only."  After you've made your selection, click the button below labeled Edit MAC Filter List.

Enter the MAC addresses into the filter list, with a colon (:) in between each pair of characters, just like the MAC addresses were displayed in the DHCP clients table.  (If you've forgotten a MAC address of a connected device, you can view currently-connected devices by clicking the Wireless Client MAC List button at the top of the window.)  Once you've entered all of your MAC addresses, click Save Settings.  When the "Settings are successful" message appears, click Continue.

The MAC Address Filter List window will still be open; if you're done adding addresses and you don't need to change anything, you can close it.  In the Wireless MAC Filter page that is still up, click Save Settings to enable the filter.

MAC address filtering is now in effect.  You can modify the list of addresses at any time, or disable the filter if you want.  One nice thing about the Linksys software is that if you disable the filter, the list of MAC addresses will be saved, so if you want to re-enable it later you won't have to type all of the addresses back in.

(Originally posted on Helium.com, Jan 2011)

How to enable MAC address filtering on a Westell VersaLink 7500 DSL Gateway

Wireless networks are by definition less secure than their wired counterparts.  However, there are certain steps you can take to make a wireless network more secure, including enabling MAC address filtering through your router.  If you're using a Westell VersaLink 7500 gateway to connect to Verizon DSL service, the steps below will guide you through enabling MAC address filtering.

A.  Before you can set up MAC address filtering, you'll need a list of the MAC addresses of all the devices that you want to allow to connect to your network.  In the router's web interface, you can view the MAC address of any device currently on your network by selecting that device under My Network.  This article can also you help you find MAC addresses:  How to find the MAC address of a device.

B.  Open a web browser and type in the IP address of your Westell router.  (This is typically 192.168.1.1 by default.)  If necessary, enter your username and password.

C.  From the Main screen, click the Wireless Settings link along the top of the page.  (If you didn't have to log in before, you'll have to do it now.)

D.  Click on Advanced Security Settings on the left hand side.

E.  Under "Level 3," click on Wireless MAC Authentication.

F.  The Wireless MAC Authentication screen will appear, with instructions.  There is a box about halfway down the screen labeled "Enable Access List" - put a check in the box and then click Apply.

G.  A box will appear to let you know that your wireless access will be temporarily interrupted; click OK.

H.  Click the Add button toward the bottom of the page.  On the next screen, enter the MAC address of the first device you want to allow.  (You can use MAC address filtering to block specific devices as well; if you're entering an address to block, make sure the drop down box next to Traffic is set for Blocked.)  You can enter a descriptive name if you want to, then click Apply.

I.  The address you entered will appear in the box above "Add."  To enter more addresses, click Add again and follow the same procedure for each MAC address.

Once you've added all of the devices that you want to, make sure you can get online from each of them.  A single typo when inputting the MAC address will prevent that device from accessing the Internet.

If you get a new computer down the road, or if someone else wants to get on your network, you'll need to add that MAC address to your list.  You can edit or delete an entry by clicking on the address in the box and selecting the appropriate button, Edit or Delete.  To disable MAC address filtering, go back to the Wireless MAC Authentication page, remove the check mark next to Enable Access List and click Apply.

(Originally published on Helium.com, Sept 2010)