Types of VPNs

Understanding the types of VPNs is essential to choosing the right solution for your organization's needs. The two main types are site-to-site VPNs and remote-access VPNs.

A site-to-site VPN connects two or more separate networks, such as a company's headquarters and its branch offices. This type of VPN creates a secure tunnel between the networks over the internet, allowing devices in each location to communicate as if they were on the same local network. Picture two office buildings, each with its own local network, joined by a secure, encrypted "bridge" across the internet. A common scenario is a company with offices in different cities that need to share files and resources securely.

A remote-access VPN allows individual users to connect securely to a private network from any location. This is especially useful for employees working from home or traveling. The user's device runs VPN client software, which establishes an encrypted tunnel to the organization's VPN server. Imagine an employee at a coffee shop using their laptop to connect safely to the company's internal network, accessing files and applications as if they were in the office.

Below is a simple diagram to help you visualize the difference:

Site-to-Site VPN:

[Branch Office Network] <---VPN---> [Headquarters Network]

Remote-Access VPN:

[Remote User] <---VPN---> [Company Network]

Each type of VPN has its own set of use cases. Site-to-site VPNs are ideal when you need to securely link multiple fixed locations, while remote-access VPNs are best for supporting mobile users or employees working from outside the office.

Organizations choose between site-to-site and remote-access VPNs based on their operational needs. Site-to-site VPNs are most commonly used by companies with multiple branch offices that require constant, secure communication between locations. This setup ensures that resources like file servers, databases, and printers are accessible to staff in any connected office, without exposing sensitive data to the public internet.

Remote-access VPNs are favored when employees, contractors, or partners need secure access to the organization's internal network from remote locations. This is especially common in organizations with a distributed workforce or those that support work-from-home policies. With a remote-access VPN, users can log in from anywhere with an internet connection and work as if they are physically present in the office.

In some cases, organizations deploy both types: site-to-site VPNs for inter-office connectivity, and remote-access VPNs for mobile or remote users.

# OpenVPN remote-access client configuration example
client
remote vpn.example.com 1194
proto udp

This configuration snippet is for a remote-access VPN client using OpenVPN. The client directive tells OpenVPN to operate in client mode, which means it will initiate the connection to a remote VPN server. The remote vpn.example.com 1194 line specifies the address and port of the VPN server the client should connect to—here, vpn.example.com on port 1194. The proto udp line sets the protocol to UDP, which is commonly used for VPN connections due to its efficiency and speed. Together, these settings allow a user's device to securely connect to the organization's network from any location.