Written by Joseph Currao
This article covers VPN technology from basics to use cases.
VPNs, or Virtual Private Network, serve many purposes. They can allow you to access your home network remotely, secure your web communication, work from home, etc. There are many products and solutions available, some being free, subscription-based, or DIY. In this article, we are going to explain how it works and why you would want to use it. Let’s dive in to get a good understanding.
So how does it work?
VPNs work by creating a point-to-point connection over existing networks, typically with tunneling protocols. They can also use dedicated circuits, but for most people, we wouldn’t ever use this. A tunneling protocol essentially repackages traffic data into a different form. This is a critical piece of the VPN puzzle, because it serves as the basis for encrypting your traffic. It’s exactly as simple as it sounds. Think of a virtual network tunnel connecting you (host) to the other end (server). To everyone else, they just see scrambled traffic. But within your own tunnel, you can safely communicate with the server. There are many ways to encrypt your traffic, with L2TP (Layer 2 Tunneling Protocol) with IPSEC (IP Security) or OpenVPN being some basic examples. In order to negotiate a successful VPN session, your device (client) would need to be configured to match the configuration requirements of the VPN server, or host. Some configuration requirements include an IP address (or domain), user name, password, PSK (pre-shared key), VPN method, etc. The IP or domain you privde during the configuration process will tell your machine where to go/find the VPN server. The protocols you select will tell you how to negotiate with the server, while the credentials will authenticate your connection.
Once you have successfully connected to your server, your machine will receive a new IP address from the VPN server that allows you to use the VPN network. Depending on how the VPN server is configured you may or may not see local hosts on the network. From here it’s possible to see files on machines in the network if configured properly. Your web traffic will likely now originate from this web server as well. So when you go to a website, the website thinks it’s your VPN server accessing it, not your machine.
When you are done using the VPN connection, simply disconnect and your machine’s web presence is back where you started. Try going to whatsmyip.org while connected to your VPN. Disconnect, then refresh the page and watch your IP address change.
Why use it?
You can connect to a VPN server from anywhere in the world, as long as the Country, ISP, and your network, and your machine/client allow it. Some countries actively block VPN services because it prevents them from snooping/spying on your communications. Some ISPs or organizations block VPNs for the same reasons, often requiring approval for use. A typical VPN port is UDP 1194. One easy to way to prevent a VPN from working is to block this port at the firewall. When you do this, the request made by the host will never leave the local network and your VPN connection will fail. Going to a different port would bypass this however, so you would typically want to block protocols among other measures if you really want to prevent this from working. I am only mentioning this because if you feel like you’ve configured your VPN correctly and it is still not working, there may be other factors at play.
Configuring your client
Windows 10, Android, iOS, and OS X have VPN clients build in. You would simply use their clients by configuring them to match the server requirements. It’s pretty straightforward and doesn’t require a lot of setup.
In some cases, the built-in VPN client from your operating system isn’t enough. OpenVPN allows you to export a configuration file which often contains certificate information. You’ll need to download and install additional software to your machine in order for this to work. This is a common option for people running their own VPN servers at home and abroad. Another option is with subscription based VPNs like PIA (or Private Internet Access) which provide all-inclusive GUIs (graphical user interface) and include everything you need to anonymize your traffic. You can use PIA on Windows, Linux, Mac, iPhones, and Android devices, etc.
Once you understand how a VPN works, many possibilities start popping up. Here’s a few good ones:
- Access your home network remotely – Traveling any where in the world with an internet connection? If you need a file off a home computer or server, use a VPN to log in and copy what you need to your personal device. This comes in handy if you need a document, photo, etc. but forgot it at home. You can even use this to access home devices like Tivos in order to watch a show anywhere in the world or want to print a document at home.
- Change your machine’s web location – Are you in Italy but want to appear on the web as though you are in the US? Selecting a VPN server that resides in the country you prefer will make your machine appear as though it is in the country. This often bypasses region restrictions and search results will be catered towards the country of your VPN server location. This can be useful when trying to bypass restrictions by country or region, or for getting more relevant information.
- Work remotely – More and more companies allow you to work from home these days. In order to access services and data at your job while being at home, you’ll need a VPN connection. This also allows your employer to monitor web traffic on your machine to validate your daily internet use (just the same as being on-site) which also allows you to take advantage of their enterprise security tools to protect your machine from malicious content. When you finish work for the day, simply disconnect from the VPN and you can enjoy personal web browsing again.
- Safer web browsing – If you ever use free/open WiFi at a public place like a coffee shop or hotel, a savvy computer person can sniff out your web traffic and gain access to sensitive information including passwords. With a VPN, you can still use open WiFi, but now all of your traffic is encrypted whether you’re visiting an HTTPS site or not. That’s because every bit of data that leaves your browser will be encapsulated by your VPN tunnel. The hacker will not see any sensitive data, and you can browse the web, do online banking, and chat with no stress. This is probably the best use case for the every day person to justify the cost of a premium VPN service.
I hope this gives you a better understanding on what a VPN is. VPNs are a critical networking technology that is used much more often than you can imagine. If you don’t use it already, I am sure at least one use case mentioned above would benefit you in one way or another.
Note: I mentioned Private Internet Access in this write up, but we are in no way specifically endorsing them or advertising on their behalf. Even though we personally use PIA, there are many other great VPN solutions out there including ExpressVPN, IPVanish, PureVPN, and more. It’s important to pick a VPN that does not log your traffic. The less personal information you share to the web, the better.