In the big, interconnected realm of the internet, end-to-end communication (ideally private and secure) is critically important. That’s where Virtual Private Networks, or VPNs, step in. Think of them as invisibility cloaks for everything you do online, keeping you hidden and protected from anyone who might want to snoop. So, how do these VPNs work, and why should we care about them? Let’s explore in simple terms to get a clearer picture of VPNs.

What is a VPN?

VPN is a special technology that creates a (usually) protected network connection over a public network, such as the internet. Although this connection is technically virtual, it effectively allows for connecting specific endpoints that wish to communicate, such as VPN gateways or user devices.

Most VPNs provide certain security functions, with encryption being the most common. Encrypted data are unreadable to anyone who might intercept it, ensuring your online activities, from the sites you visit to the files you download, remain private and secure.

VPNs are used in various scenarios, such as:

• At Home – Individuals use VPNs to protect their privacy online, access region-restricted content (like streaming services), and secure their transactions
• In the Workplace – Businesses employ VPNs to allow employees to securely connect to the company’s network from remote locations, protecting sensitive data
• While Traveling – Travelers use VPNs to secure their internet connection on public Wi-Fi networks, which are often unsecured and pose privacy risks

VPN Types

When we talk about VPNs, they generally come in two flavors: remote access VPNs and site-to-site VPNs. Both serve the primary purpose of establishing internet connections and enabling data to be exchanged securely over a public network, but they fit to different needs and setups:

• Remote Access – connects an individual user to a remote network. This type of VPN creates a secure tunnel from the user’s device (like a laptop or smartphone) to the VPN server, and from there, securely accesses the corporate network as if they were directly connected to the network’s servers. This setup is ideal for employees working remotely or for any individual who needs to access a network securely from a distance (e.g. imagine you’re working from home or a coffee shop and need to access files on your company’s network securely). Another good example here is secure browsing (SSL/TLS), such as for instance when you connect to your bank’s website
• Site-to-Site – Also known as LAN-LAN, it connects entire networks to each other, allowing users in one location to securely access resources and servers in the other location as if they were all on the same local network (e.g. you’ve got two separate office locations that need to connect their networks securely over the internet)

VPNs are also categorized into two types based on the networking layers they operate on – Layer 2 (L2) and Layer 3 (L3):

• L2 VPNs: These VPNs work on the data link layer, which is responsible for communication between adjacent network nodes. An L2 VPN essentially allows you to bridge two physical networks over the internet, making them appear as if they are on the same local network. It’s like creating a direct, private road between two houses in different cities
• L3 VPNs: Operating on the network layer, L3 VPNs route data through a virtualized network path. This is more like setting up a secure postal service across the entire country, where the data packets are like letters sent between cities, with the VPN ensuring they’re delivered securely and privately

VPN Security

Not all VPNs offer the same level of security. Generally, it’s crucial to select a VPN technology that aligns with the specific use-case or scenario at hand:

• GRE VPNs are considered insecure because they focus on wrapping data packets for transportation through a tunnel but don’t inherently encrypt them. Imagine sending your secret letter with a note saying “Please don’t open,” but not locking it. It’s more of a request for privacy than a guarantee
• IPsec VPNs, on the other hand, not only encapsulate data packets but also encrypt them, offering a higher level of security. This is like sending your secret letter in a locked box, ensuring that only the recipient can open it and read the contents
• Similarly, SSL/TLS VPNs secure data at the transport layer, providing robust encryption for web-based applications. They enable secure remote access to network resources, allowing users to safely transmit sensitive information over the internet. This can be compared to sending your message through a secure online messaging service where messages are encrypted end-to-end

Advanced VPN Technologies

As technology evolves, so do VPNs. If you’ve already been studying the topic of VPNs, you’ve probably come across two advanced technologies that have emerged: Group Encrypted Transport VPNs (GETVPNs) and Dynamic Multipoint VPNs (DMVPNs).

• GETVPNs are generally meant to be deployed across WAN environments. Unlike traditional VPNs, which establish point-to-point connections, GETVPNs allow for the establishment of a secure group of network devices, enhancing efficiency and scalability
• DMVPNs offer a dynamic solution by allowing secure connections to be created on-demand between sites without the need for a pre-established network path. This flexibility makes DMVPNs ideal for organizations with rapidly changing network topologies

To sum it up, VPNs play a crucial role in keeping our digital activities private and secure. No matter if you’re surfing the web at home, exploring new places, or handling business matters, using a VPN can greatly improve your privacy and security online.