All of the laptops manufactured these days have built-in wireless adapter/wi-fi. Most of the people these days have their own wireless adapter connected to their desktops. Don’t you know that they can connect to someone else’s network wirelessly?If you do have wireless router, gateway or other wireless networking devices (ex. WRT54G-LINKSYS wireless router or WCG200 for gateway), don’t you know that you can connect 21 wireless PCs to it? And if your router is not secured, don’t you know that someone in your area having built-in Wi-Fi on their PCs can connect to your own network without even noticing it. Maybe you’ll find one day that you are having slow internet connection because of too many users doing multiple applications in your network. Or if you subscribe for fast internet connection to your ISP, maybe you’ll might not even notice that you’re not the only one connected to your internet.

HOW CAN I CHECK IF SOMEONE IS ACCESSING MY ROUTER?

Do you have Linksys router? You can check it on your router’s setup page! Here’s an example of checking other computers on Linksys router.

1. Check your PC’s/PCs MAC address. Write it down on a piece of paper. How to do that? Check my article: “HOW TO CHECK MY COMPUTER’S MAC ADDRESS“.

NOTE: In Windows 2000 or XP, MAC address is the same with “Physical Address”. In Windows 98 or lower version, it is called “Network Address”.

2. Access router’s set-up page. If you do have Linksys router and don’t know how to do that, go to my article: “HOW TO ACCESS LINKSYS ROUTER’S SET-UP PAGE“.

3. Go to “Wireless” tab.

4. Under “Wireless” tab, go to “Wireless Network access” or “Wireless MAC Filter“.

5. Click “Edit MAC Filter List”

6. You will see “Wireless MAC Client” window. On this window, you will see “ACTIVE PC” option. Listed here is the MAC Address connected to your router. Now, match the MAC address of your PC from the MAC addresses listed there. Did you see MAC address that does not belong to your PC/PCs? That may be someone else’s PC. Then, try to enable MAC filter. Do you know how to enable MAC filter? Go to my article: “HOW TO SETUP WIRELESS MAC FILTER ON A LINKSYS ROUTER?“.