First let me say that the Mac Address has nothing to do with Mac computers. I could explain what a mac address is, but it would be much easier to refer you to this web site for a definition, www.webopedia.com/TERM/M/MAC_address.html

Now that you know what a mac address is, I will continue. A LAN or Local Area Network can use Mac Address Filtering to prevent a user from accessing the Internet using their Network. This is done by going to a router utility setup web page provided by the maker of the router you might be using. Check your router manual or contact the maker to find out how to access the setup page, the address is usually similar to 192.168.?.?. Once you have located the setup page and you locate the setting for Mac Address Filtering, just activate it and one at a time enter the Mac Address of each computer that you would like to allow on your network. Anyone trying to access your network who is not on your list, will be denied access.

Here is how to find the Mac Address for your computer. Go to START, RUN and type in CMD, the CMD.EXE window will open and the cursor will be blinking. Type in "ipconfig/all" without the quotation marks and click Enter on your keyboard. If the search produces nothing, try typing "ipconfig/ all" with a space between the / and all. After the search you should see where it says "Physical Address", the twelve digit numbers and letters that follow the Physical Address will be your Mac Address. In the event that "Physical Address" appears more than once, look for the one that appears after the name of your ethernet card.

So if you are traveling in your RV and decide you would like to let someone access your network, tell them how to find their Mac Address and enter it into your router setup web page.