mac filtering

What is MAC Address Filtering and How Does It Work?

Don’t confuse your MAC address with an IP address. 

They might sound the same when you read about them on the internet, but clearly, they are not. A device can have a different IP address every time you connect it to the internet but always the same MAC address. In fact, the MAC address is how your IP address is assigned. In this article, we will tell you all about MAC Address filtering and how to disable it should you so desire. 

What is a MAC Address?

A MAC (Media Access Control) address is a 12-character unique code that is assigned to every internet-connected device. 

Your iPhone’s MAC Address will be different from your laptop’s. A MAC address is assigned by the IEEE to various internet-connected devices in hexadecimal format in the form of 00-00-00-00-00-00. (You can look up vendors and more at this link; every single device has specific assignments and it is actually easy to find out the vendor of a specific device based on its MAC address.) These characters include unique numbers and letters (0-9, a-f as in hexadecimal).    

MAC address filtering is a process that can block or allow specific MAC addresses to stay connected on your local network. If you wish to gain internet access rights to any local or wide area network, you can do that via MAC addresses. 

For example, if your computer’s MAC address is whitelisted on a specific network then you can use that unique identifier (which is your MAC address in this case) to access the internet. 

In this way, the term MAC address filtering was coined because it filters out whitelisted and blacklisted addresses. 

Whitelisted addresses: MAC addresses or devices that have access to the internet. 

Blacklisted addresses: Those addresses that can’t access the internet after filtering. 

MAC addresses can be either whitelisted or blacklisted, so if your device’s identifier is denoted as being abusive, you may find out you’re blacklisted and won’t ever be able to connect to your network. After all, it’s easy to spoof an IP address, but not as easy to spoof your MAC address without getting a new device altogether or trying a few more-or-less complex adjustments in your device’s control panel.

How Does MAC Address Filtering Work

Let us ELI5: explain it like I’m five. 

Imagine you have connected two devices on your internet router with MAC addresses, one with 00:31:55:ad:0b:c9 that belongs to Tom’s iPhone and 0a:b3:c8:f1:44:d0 that belongs to Sansa’s laptop. 

If you add Sansa’s MAC address to the filtering list and select block and allow the rest option, then the router will reject Sansa’s request and she can’t access the internet. Tom, on the other hand, can get in. 

On the other hand, if you choose the allow and block the rest option then Sansa can use the internet and Tom won’t be able to connect to the router. This is how MAC address filtering works in general.   

The Quickest Way to Find MAC Address on Your Computer

You can use the command prompt to check your device’s MAC address. If you haven’t done that before, there is no need to worry. You don’t require any technical skill for that. 

All you have to do is type and search cmd, and when the prompt appears, type ipconfig /all and press the Enter button. 

You will get something like this: 

Your Physical Address: 68-17-29-45-02-BB is the MAC address of your computer’s Ethernet card. Notice that if you connect to the internet on an Ethernet card connected embedded in your motherboard but you attach a separate Ethernet card or USB wireless Ethernet card, that device has a separate MAC address too. 

How to Enable MAC Address Filtering

You can block unwanted or suspicious connections via MAC address filtering. All you have to do is tell your router to allow specific MAC addresses and block others. 

Here’s how to enable MAC Address filtering: 

Step 1: Select Firewall > Advanced Settings > MAC filtering.    

Step 2: Tick the box that says Enable

Step 3: Select Block and Allow the Rest to completely block incoming traffic of specific MAC addresses and allow every other address that is connected to the network. 

Step 4: Select Allow and Block the Rest to give access to specific MAC addresses and block incoming traffic from other devices.  

Step 5: Choose Add on the MAC addresses table. 

Step 6: Type in specific MAC addresses to block/allow on that table. 

Step 7: Select Save and repeat the same for every MAC address that you wish to block or allow on your router. 

Step 8: Choose Save and you are done

How to Disable MAC Address Filtering

MAC address filtering is best for enhancing internet security. You should think about disabling MAC filtering if you frequently add or remove devices or you are using an open local network. Here’s how to do it on your computer: 

Step 1: Type and search for cmd to open the Command Prompt on your computer. 

Step 2: Now, type ipconfig and press the enter key. 

Step 3: Check and note down your default gateway on the file. 

Step 4: On your web browser, type your default gateway and press the enter key. 

Step 5: Log in using your admin credentials. Type admin as both the username and password. 

Step 6: Go to Advanced settings > MAC filtering > Access Control

Step 7: Find the drop-down option on MAC filtering, choose Disable.   

Step 8: Select Apply or Save to save your router’s settings. 

Why You Should Disable MAC Address Filtering  

Hackers can check MAC addresses by continuously monitoring your incoming internet traffic. Once an attacker traces and finds a MAC address, he can quickly change the existing MAC address with a new one and penetrate your local network. 

Attackers are clever buggers and use various tools to determine internet data packets that you are receiving on your device and run commands to disassociate those packets. Some of the reasons why you should think about disabling MAC address filtering are: 

  • Takes a lot of time: Finding MAC addresses of every single device on your local network and putting them on the list can be taxing. Imagine this: you have to manually enter your friend’s or neighbor’s MAC address on the router every time they decide to swing by your place and want to use the internet. 
  • WPA2 encryption works: Creating a complex password using every special key on your keyboard with WPA2 encryption can make it hard for attackers to crack into your network. The bottom line is: always create passwords that are hard to guess for an internet attacker who is probably way smarter than you. 

Secure your private network… 

MAC address filtering falls into the category of administrative rights instead of security. This process may not stop attackers from snooping into your network. To make a long story short, go for the best security option to deal with regular internet threats.  

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Sameed Ajax Sameed is a Digital Content Producer at PureVPN who covers cybersecurity, streaming, and weekly news. Besides that, he wastes time playing FIFA, eating pizza, and sending tweets.

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