Security

Types of virtual private network (VPN) and their protocols

The two families of virtual private network, remote access and site to site, and the protocols behind them: IPSec, L2TP, PPTP, SSL/TLS, OpenVPN, SSH, WireGuard.

· 5 min read · level: beginner

VPN stands for Virtual Private Network. This method allows a user to connect securely to a private network from the Internet. The VPN creates an encrypted connection called a VPN tunnel; all Internet traffic and communications pass through this secure tunnel.

Essentially 2 types of virtual private network (VPN)

  • 1. Remote Access VPN: The remote access VPN allows a user to connect to a private network and to access all its services and resources remotely. The connection between the user and the private network is made over the Internet, and the connection is secure and private. The remote access VPN is useful for home users and for business users. An employee of a company, while away from the workplace, uses a VPN to connect to the company's private network and to access files and resources on the private network remotely. Some VPN users mainly use VPN services to get around regional restrictions on the Internet and to reach blocked websites. Security-conscious users also use VPN services to improve their Internet security and their privacy.
  • 2. Site to Site VPN: A site-to-site VPN is also called a Router-to-Router VPN and is commonly used in large companies. Companies or organizations with branches located in different places use the site-to-site VPN to connect the network of one office location to the network of another office location.
    Intranet-based VPN: when several offices of the same company are connected using the site-to-site VPN type, it is called an intranet-based VPN.Extranet-based VPN: when companies use the site-to-site VPN type to connect to the office of another company, it is called an extranet-based VPN.
  • Intranet-based VPN: when several offices of the same company are connected using the site-to-site VPN type, it is called an intranet-based VPN.
  • Extranet-based VPN: when companies use the site-to-site VPN type to connect to the office of another company, it is called an extranet-based VPN.

Fundamentally, the site-to-site VPN creates an imaginary bridge between the networks of geographically distant offices, connects them over the Internet and maintains secure and private communication between the networks. In the site-to-site VPN, one router acts as a VPN client and another router as a VPN server, since it is based on router-to-router communication. Only when authentication is validated between the two routers does communication start.

Illustration 1 — Les types de réseaux privés virtuels (VPN) et leurs protocoles

The types of VPN protocols

  • 1. Internet Protocol Security (IPSec): Internet Protocol Security, called IPSec, is used to secure Internet communication over an IP network. IPSec secures communication over the Internet Protocol (IP) by verifying the session and encrypting each data packet during the connection. IPSec works in 2 modes:
  1. (i) Transport mode
  2. (ii) Tunnel mode

The task of transport mode is to encrypt the message in the data packet. Tunneling mode, for its part, encrypts the entire data packet. IPSec can also be used with other security protocols to improve security.

  • 2. Layer 2 Tunneling Protocol (L2TP): L2TP, or Layer 2 Tunneling Protocol, is a tunneling protocol that is often combined with another VPN security protocol such as IPSec in order to establish a highly secure VPN connection. L2TP generates a tunnel between two L2TP connection points, and the IPSec protocol encrypts the data and maintains secure communication inside the tunnel.
  • 3. Point–to–Point Tunneling Protocol (PPTP): PPTP, or Point-to-Point Tunneling Protocol, generates a tunnel and confines the data packet. The PPP protocol (Point-to-Point Protocol) is used to encrypt the data between the connections. PPTP is one of the most widely used VPN protocols and has been used since the first version of Windows. PPTP is also used on Mac and Linux, in addition to Windows.
  • 4. SSL and TLS: SSL (Secure Sockets Layer) and TLS (Transport Layer Security) generate a VPN connection in which the web browser acts as the client and the user is given access to specific applications instead of the whole network. Online shopping websites commonly use the SSL and TLS protocols. Switching to SSL is easy for web browsers and practically no action is required from the user, since web browsers come with SSL and TLS built in. SSL connections have "https" at the start of the URL instead of "http".
  • 5. OpenVPN: OpenVPN is an open source VPN commonly used to create point-to-point and site-to-site connections. It uses a traditional security protocol based on the SSL and TLS protocols.
  • 6. VPN over SSH: Secure Shell, or SSH, generates the VPN tunnel through which the data transfer takes place and also ensures that the tunnel is encrypted. SSH connections are generated by an SSH client and the data is transferred from a local port to the remote server through the encrypted tunnel.
  • 7. Wirguard:
  • WireGuard aims to be as easy to configure and deploy as SSH. A VPN connection is established simply by exchanging very simple public keys — exactly like an SSH key exchange — and everything else is handled transparently by WireGuard. It is even able to move between IP addresses, just like Mosh. WireGuard presents an extremely basic but powerful interface.

Course to follow... ;)