When reading through websites and reviews of VPN providers, you may have seen the term “VPN Tunnel” or something similar. This term describes the actual encrypted connection between your device and the VPN server. The tunnel is used to securely transmit your data to the VPN server, to then be forwarded on to the internet.
By creating a secure tunnel between your device and the VPN server that all of your network traffic goes though, you can be confident that no-one else can monitor your internet usage. The encryption ensures that your ISP can only see the IP address of the VPN server you’re connecting to, but not any details beyond that such as what website you’re connecting to or what page you’re browsing.
Tip: It is not possible to hide the IP address of the VPN server you’re connecting to. To be able to connect to the server, the destination address must be visible. However, the rest of the data you transmit is encrypted and unreadable to your ISP or anyone else.
The effect a VPN tunnel provides resembles the effect a physical tunnel would have in real life. If you built a physical tunnel from your house to your VPN providers headquarters, it would be possible to tell that you go there, but no-one could determine what you were taking with you. Similarly, a VPN tunnel indicates that you’re communicating with the VPN provider, but not what you’re sending.
The main protocol used to create the VPN tunnel is OpenVPN. This is a free and open-source protocol with multiplatform support, no ties to a specific port making it flexible to bypass firewalls, and support for modern strong cryptography. A number of other protocols are available that do similar things, most are acceptable replacements, but you should avoid any VPN that uses PPTP. PPTP is a protocol from 1999 that includes a number of known weaknesses and does not support modern strong cryptography. Some VPN providers may still use it because it is fast, however, alternatives such as OpenVPN are not so much slower that sacrificing the security of strong encryption is worth it.