Whether you are using a VPN to bypass geo-restrictions or simply to stay safe on a public WIFI network, you will have seen the dreaded messages: You seem to be using an unblocker or proxy. Please turn off any of these services and try again. Or: We do not allow VPN/Proxies on our server, if this is a mistake please contact us.
Companies like Netflix, Hulu or Mojang Studios (Minecraft), and even governments such as in China use technology to prevent the use of VPN. This will keep you from accessing the content safely, or even from accessing it at all.
There are several ways that VPN can be blocked. The easiest and most common way is by blocking all traffic from certain IP addresses. Companies like Netflix and Hulu will notice when multiple people are sharing the same IP address and simply block that IP from getting access.
Solution: You can often solve this by choosing a different server in the same country. This will give you a new IP-address. You could also buy a dedicated IP-address in the country you want to be located. This is not cheap, but will be your private IP-address through which only your traffic gets sent.
Another way VPN gets detected is by the port that is used. Most VPN providers use the OpenVPN security protocol and traffic is usually sent to port 1194.
Solution: By forwarding it to port 443 (which is used by most traffic) you can try to blend in. This is only possible when the VPN app gives you this option in the settings, of course.
Deep packet inspection
The most advanced way to detect a VPN is by ‘packet sniffing’, which looks at much more information than just where it came from and is going to. When an OpenVPN protocol is detected, it gets denied access by default.
Solution: The best VPN providers have an advanced setting in their app which lets you connect to obfuscated servers. This will scramble your data and remove the identifying metadata to make it look like any other internet traffic.
Only the best VPN providers, like NordVPN, CyberGhost and SurfShark, can offer you the advanced settings and have multiple servers and plenty of IP addresses to bypass VPN blocks. A free VPN is never going to get you past the detection methods, because it simply doesn’t have the resources to do so. Running a VPN service costs money and extra servers, IP addresses, setting options all need to be paid for.