If your internet connection is slower than usual, then it might be because someone is using your connection. They might have gained access due to you forgetting to set a password on your WiFi router (really?). The other reason, even though it might be hard to believe, may be because someone has hacked into your router.
Now this isn’t as rare as you would like to think. We like to think that Nepalese hackers don’t have the level of sophistication that hackers from other developed countries have, but as the Internet is a global phenomenon, the skill sets aren’t limited to developed countries only.
Either way, I will show you a very easy way to determine if someone is using your network or not.
Detect intruders on your wireless network [Guide]
We will use Nmap for this article. First download and install Nmap from the link. After installation, run the ‘Zenmap GUI’. You should see a screen like below:
In the target box, enter 192.168.1.*. Choose ‘quick scan’ from the profile select box and press the ‘Scan’ button.
Nmap will take some time to scan your entire network (usually around a minute or so) and at the end will display output similar to below:
Interpreting the result
The left pane shows the number of devices on your network. In my case, there were 3 devices active at the time I scanned my network.
192.168.1.1 will usually be the wireless router.
192.168.1.2 is my iPhone
192.168.1.6 is my laptop.
If there was any intruder in my network, he/she would have shown up in the left pane. I could have simply counted how many devices were turned on in my house (including the router of course), and if the count didn’t match the number of IP addresses in the left pane, then it would be very likely that someone else was using my network.
But in this particular case, I can conclude that there are no intruders inside my network and also that there are only two other devices besides the wireless router (which has to be always on).
Hope this will help you guys. Comments & feedback are highly appreciated and welcome!