What’s a MAC Address and How Do You Find It

To ensure optimal wireless network security, a little MAC (Media Access Control) filtering couldn’t hurt. Learn what a MAC address is and how to find your’s … plus, why some online games may be dropping you.

By Ron Pacchiano

Q. Not to long ago a good friend of mine became a victim of identity theft. Trying to repair all of the damage that was done to her credit was frustrating and took what seemed like forever to resolve. Since then I have become very protective of my personal information. I bought a shredder and try not to use my credit cards online unless I really need to. This anxiety about identity theft has kept me away from purchasing a wireless router.

A while back I saw an article that you did that described how to properly set up a secure wireless network. So based on the advice in your article, I replaced my aging router with a new wireless one. I implemented all of the things you suggested. I’m using WEP with 256-bit encryption and I’m not broadcasting my SSID. One of my router’s other features that I want to enable is something called MAC address filtering. According to the documentation, this would restrict access to the network to only the PCs that have been registered with the router. So even if someone managed to get my WEP key, they still wouldn’t be able to connect to my network.

My problem is that before this, I had never heard of a MAC address or know where to find it. I know what my IP address is and tried that but it didn’t work. Could tell me exactly what a MAC address is and how I go about finding it? Thanks.

A. Sorry to hear about your friend’s identity theft issues and I understand your concerns with wanting to be as secure as possible. Just remember restricting access to your wireless network isn’t enough. Make sure you have a good anti-virus package with constantly updated virus definitions installed and running on your PCs at all times. Also, you should always be performing Windows Critical updates as well as using adware removal tools (like SpyBot Search and Destroy or Ad-Aware) periodically to eliminate any possible threats to your system.

While your wireless network is already pretty secure, it doesn’t hurt to enable MAC filtering as well. So to answer your question, MAC is an acronym and stands for Media Access Control. The MAC address (also known as the physical address) is your computer’s unique hardware number. When you’re connected to the Internet from your computer (or host as the Internet protocol thinks of it), a correspondence table relates your IP address to your computer’s physical (MAC) address on the LAN. This is how the router knows where to send IP packets destined for your system.

Identifying your MAC address is easy. In most cases, it is physically printed on the adapter itself. On a laptop with a PC Card based adapter this is easy to see. Just disconnect the card and flip it over. On a PC or a laptop with an integrated network adapter you need to find it using software. The process is almost identical to the utility you use to see your systems IP address. On a Windows 2000 or Windows XP machine that would be IPCONFIG. To see the MAC address you need to add the switch /ALL to the command. For those not familiar with it the sequence of steps is as follows:

  • Click on START, and then click on RUN.
  • The RUN dialogue box will appear. Type CMD and press ENTER.
  • A DOS window will appear. This is also commonly called a Command Prompt.
  • Now type IPCONFIG /ALL at the command prompt and hit ENTER. This window will now display the configuration of all of your network adapters. If you have multiple network adapters in your PC you’ll see multiple addresses. The MAC Address you’re looking for will be listed under the heading Ethernet adapter Wireless Network Connection.
  • Now look for the Physical Address. It should look something like 00-50-BA-D1-BA-71.
  • To close the window when you are finished, type exit at the command prompt and hit the Enter key.

Now that you have the MAC address in hand, just follow your routers documentation for setting up the MAC Filter. By the way: Don’t forget to change your routers default password. This is a common security hole that many people forget about. Good Luck!


Q. I have a D-Link wireless router that I use for all of my PCs and my Xbox. For my birthday, a friend of mine had given me Xbox Live. We set it up and have been playing with it ever since. The other day we tried playing a game, but just couldn’t get it to work. Other games we have work fine, but ever so often we come across a title that just doesn’t seem to work properly. Sometimes we can be in the middle of a game and I’ll lose the connection for no apparent reason. Do you have any idea why I have trouble hosting some games or experience connection problems with XBox Live?

A. You didn’t really leave me a ton of information here so it’s difficult to say exactly what your problem might be. It would have been good to know specifically which games were giving you problems and what time of day you most noticed your connection getting dropped. But I’ll give it a shot, anyway. Based on what I know, all I can tell you is that in order for Xbox Live to operate correctly the following ports must be available:

  • UDP 88
  • UDP 3074
  • TCP 3074

To reiterate, these ports apply for Xbox Live ONLY. Depending on the video game or application that is being used, you may be required to open additional ports. This is why I need to know the specific games you’re having trouble with. Also, you have to remember that Xbox live is a network just like any other. They do experience problems from time to time and there are certain times of day when network traffic is going to be heavier than others. So you might on occasion experience network lag or dropped connections. For more information you could try contacting Xbox Live Support or visiting http://www.xbox.com/en-us/live/connect/router.htm for tip on optimizing your online game play.