Introduction to Virtual Private Network (VPN)

by Billy J Long Guidance, PSA Articles

Article (PSA‑0009) – Introduction to Virtual Private Networks (VPN)

A Virtual Private Network (VPN) creates an encrypted “tunnel” that carries your Internet traffic through a public network (the Internet) to a private network – typically your workplace, home network, or a commercial VPN server. All data that travels through the tunnel is cryptographically protected, so anyone who intercepts the traffic sees only gibberish.

What Can You Do With a VPN?

  • Network security & privacy – Public Wi‑Fi (coffee shops, airports, hotels) is a hot spot for “sniffing” attacks. A VPN encrypts every packet, preventing eavesdroppers from seeing which sites you visit or what credentials you type.
  • Remote access to work or home resources – Once connected, you appear to be on the same LAN as the VPN server. You can reach file shares, internal web apps, printers, databases, and other services that are otherwise blocked from the public Internet.
  • Access geo‑restricted content – By selecting a server in another country you can make websites think you are physically located there, letting you watch streaming services, use region‑locked tools, or test websites from multiple locales.
  • Bypass censorship – In countries where governments block social media, news sites, or messaging apps, a VPN routes traffic through a server outside the jurisdiction, restoring open Internet access.

How a VPN Works

A VPN consists of two main components:

  1. VPN client – Software you install on a device (Windows, macOS, Android, iOS, Linux, routers, etc.). The client authenticates to the VPN server and negotiates an encrypted tunnel.
  2. VPN server – The endpoint that receives your traffic, decrypts it, and forwards it to the destination network (or out to the public Internet). The server also enforces authentication (username/password, certificates, MFA) and may apply additional policies such as split‑tunneling or DNS filtering.

All traffic inside the tunnel is encrypted with modern ciphers (AES‑256‑GCM is the current standard). When the tunnel is up, the client routes either all traffic (full‑tunnel) or only selected traffic (split‑tunnel) through the VPN.

Common VPN Protocols (2025)

  • WireGuard – Fast, simple codebase, strong modern cryptography. Typical use: modern commercial VPNs and self‑hosted solutions.
  • OpenVPN (UDP/TCP) – Widely supported, mature, highly configurable. Typical use: enterprise remote‑access and cross‑platform compatibility.
  • IKEv2/IPsec – Excellent for mobile devices (auto‑reconnect), strong security. Typical use: corporate mobile‑device VPNs.

Should You Use a VPN?

Even if you never need to reach a private network, a VPN adds a useful layer of protection whenever you use public or untrusted Internet connections.

Benefits

  • Encrypts traffic, defending against passive eavesdropping and active “man‑in‑the‑middle” (MitM) attacks.
  • Hides your real IP address, making it harder for trackers or malicious sites to profile you.
  • Allows secure remote work without exposing internal services directly to the Internet.

Potential Downsides (and how to mitigate them)

  • Performance impact – Encryption adds overhead. Choose a fast protocol (WireGuard), a nearby server, and a reputable provider with sufficient bandwidth.
  • Trust in the VPN provider – The provider can see your traffic. Opt for a no‑logs policy, audited by a third party, or run your own self‑hosted VPN (e.g., a Raspberry Pi running WireGuard).
  • Split‑tunneling vs. full‑tunnel – Split‑tunneling improves speed but may leak DNS or other traffic. Enable DNS‑leak protection and a “kill switch” that blocks traffic if the VPN disconnects.

Best‑Practice Checklist

  1. Select a trustworthy VPN (no‑logs, reputable jurisdiction, independent audit).
  2. Use modern protocols – WireGuard or OpenVPN with AES‑256‑GCM.
  3. Enable a kill switch to prevent accidental exposure if the tunnel drops.
  4. Configure DNS‑leak protection – ensure all DNS queries travel through the VPN.
  5. Prefer full‑tunnel for public Wi‑Fi unless you have a specific reason for split‑tunnel.
  6. Combine with MFA for the VPN authentication step.
  7. Keep client software up to date – VPN apps receive security patches just like any other software.

When to Consider a Self‑Hosted VPN

If you need full control over the server, have compliance requirements, or simply want to avoid any third‑party logging, you can install a VPN on your own hardware:

  • Raspberry Pi or small Linux box running WireGuard or OpenVPN.
  • Edge/router‑based VPN (many ASUS, Netgear, and Ubiquiti routers include built‑in VPN servers).
  • Cloud VM (e.g., AWS Lightsail, DigitalOcean) with a VPN installed for remote‑access to cloud resources.

Bottom Line

For everyday users, a reputable commercial VPN provides a quick, user‑friendly way to protect privacy, secure public‑network use, and reach remote resources. For businesses, pairing a corporate VPN with a zero‑trust architecture (MFA, least‑privilege network policies, and conditional access) offers the strongest protection.

Disclaimer

This article is for **informational purposes only**. PSA Computer Services does **not** provide VPN services, nor do we sell, install, or manage VPN solutions. For assistance selecting a VPN provider or setting up a self‑hosted tunnel, please consult a qualified network or security specialist.

“There is wisdom in a multitude of counselors.”