VPN Tunnel: What It Is and How It Works

Among the various cybersecurity tools available, many people are favoring virtual private networks (VPNs). The number of people using VPNs has increased amid ongoing threats to internet security and freedom worldwide. According to Statista, 23.2 percent of internet users globally access the internet through a VPN [1]. 

Furthermore, even with government restrictions imposed, the adoption of VPNs in Russia has seen a notable rise in popularity. According to Statista, 36.2 percent of the country's population subscribed to VPN services in 2023 [1].

Notably, the widespread global adoption of virtual private networks isn’t without reason. From online security to privacy, a VPN offers several benefits. Two significant benefits include the security aspects of VPN tunneling and its data-transferring mechanism over networks. Gain further insight into VPN tunneling, including its benefits, methodology, use cases, and more below.

What is a VPN tunnel?

VPN tunnels are private connections surrounding your internet data, encrypting the data packets sent from your computer or other connected device. A VPN establishes a secure tunnel to the internet, encrypting and routing all data originating from any device connected. The tunnel enables remote users to securely connect to a corporate network in a business setting. 

How does VPN tunneling work?

VPN tunneling captures and encrypts data using protocols to protect data coming from and going to your devices. It’s important to understand how data transmission happens over the internet to understand VPN tunneling. 

Data transmission over computer networks involves dividing the data into smaller units called packets, which are subsequently transmitted over the network and reassembled at the destination.

VPN tunneling utilizes data encapsulation and encryption to transport data traffic through a potentially insecure network securely. Data encapsulation separates the data packet from other data transmitting through the same network. Encryption then ensures that the data becomes unreadable and unidentifiable, even to highly skilled malicious actors.

Remember, to use VPN tunneling, you must first subscribe to a VPN service and establish a connection with a server for browsing. When you browse the internet using a VPN, your ISP and the websites you visit cannot see your IP address. Instead, only your VPN provider’s IP address is visible, ensuring your privacy.

Types of VPN tunnel protocols

VPN tunneling protocols provide rules for encrypting and transmitting data. When using a VPN, you can choose from several protocols. Explore each tunneling protocol in detail below.

1. PPTP

Point-to-point tunneling protocol (PPTP) is an older VPN protocol still used today due to its fast connection speeds. However, this speed comes with a tradeoff: The protocol has weak data encryption, making it susceptible to attacks. 

In typical instances, networks that rely on PPTP must implement supplementary security measures to compensate for the protocol's weak security. However, such actions often result in losing the protocol's advantages. PPTP is typically only advised in scenarios requiring legacy support and where security is not the main issue.

2. L2TP/IPSec

Layer 2 tunneling protocol (L2TP)—in tandem with internet protocol security (IPSec)—is an improvement over PPTP. This protocol offers dual protection, with L2TP and IPSec creating their own encryption for added security. However, the double encryption by L2TP/IPSec may result in slower connection speeds. Additionally, some firewalls may block L2TP/IPSec due to the use of fixed ports.

3. SSTP

One distinguishing feature of the secure socket tunneling protocol (SSTP) is that it is exclusive to Windows operating systems. With native support on Windows 7, 8, and 10 platforms, SSTP provides greater security than PPTP or L2TP/IPsec. Additionally, SSTP does not rely on fixed ports, which enables it to bypass firewalls. However, the drawback is that this protocol is not accessible to users with non-Windows operating systems. This can limit its availability.

4. OpenVPN

OpenVPN is a secure VPN tunneling protocol developed with open-source software, using (secure socket layer) SSL encryption. It is fast and can bypass VPN-blocking software. That said, you may need third-party client software to set it up on Windows, Mac, and Linux operating systems, among others.

Did you know?

The Cybersecurity and Infrastructure Security Agency (CISA) and the National Security Agency (NSA) offer a framework for selecting VPNs, configuring VPN gateways, and securing VPN infrastructure to help prevent cyberattacks.

Pros and cons of VPN tunnels

VPN tunneling involves using a VPN service, which means that its operation is essentially the same as that of a VPN. While VPNs have several benefits, they also have some limitations. The following are some significant pros and cons associated with using a VPN service.

Advantages

• Protects data from unauthorized access or theft

• Ensures digital anonymity by masking devices’ IP address

• Averts bandwidth throttling by ISPs

Disadvantages

• Using a VPN may result in a drop in internet speed

• VPNs may not work with all devices 

• The use of VPNs is illegal or punishable in select countries 

Read more: The 3 Types of Network Protocols

Usage scenarios: How and where to utilize VPN tunnels?

VPN tunnels check many boxes for businesses and privacy-conscious users.  Below are several use cases concerning VPNs.

Stream content from any location

Due to licensing restrictions, streaming platforms have varying content libraries across different countries, which leads to the practice of geo-blocking. However, using a VPN, you can alter your perceived location (IP address) on the internet to access content from a location the service deems acceptable.

Secure remote access for teams. 

A remote access VPN allows employees to connect to an organization’s network infrastructure securely, including its applications, tools, and data. A VPN encrypts all traffic sent and received, providing a secure connection between the user and the corporate data center—even when using a public internet connection.

Read more: Information Systems vs. Information Technology (IS vs. IT)

Next steps

A VPN tunnel is the protocol that masks your IP address and encrypts your online traffic when using a virtual private network. VPNs allow private users and businesses to connect and use the Internet securely. If you’re ready to gain a deeper understanding of VPN tunnels and how to establish them, get to know the finer nuances of virtual private networks with just two of the VPN-related courses you can find on Coursera: Connect and Protect: Networks and Network Security offered by Google and Networking Fundamentals from Akamai.