MAC address filtering is a technique used to deploy device-level security on a wireless LAN. Because every wireless device has a unique MAC address, wireless routers and access points can prevent wireless devices from connecting to the network if the devices do not have authorized MAC addresses. To enforce MAC address filtering, enter the MAC address of each wireless device.

To set up a MAC address filter, as shown in the figure, follow these steps:

Step 1. Select Wireless > Wireless MAC Filter.

Step 2. Select Enabled.

Step 3. Select Prevent or Permit for the access restriction type.

Step 4. Click Wireless Client List.

Step 5. Select the client.

Step 6. Click Save to MAC Address Filter List > Add > Save Settings > Continue.

Repeat the steps above to add more wireless clients to the MAC Address Filter List.

The MAC address of a wireless NIC can be found by typing ipconfig /all at the command prompt. The MAC address is labeled Physical Address in the output. For devices other than computers, the MAC address is usually on the label of the device or within the manufacturer’s instructions.

Filtering MAC addresses can be tedious if a lot of devices are connected to the network. Also, when using MAC address filtering, it is possible for an attacker to sniff a MAC address using wireless hacking tools. After the attacker has the MAC address, it can be used to impersonate the computer that has been approved through MAC address filtering. Use a strong encryption technology instead.