How VPN Works (2025): From Encrypted Tunnel to New IP

A VPN (Virtual Private Network) is often described as “a secure tunnel,” but what actually happens when you press Connect? In 2025, VPN apps are fast and polished — yet the core idea is still simple: encrypt traffic, route it through a VPN server, and present a different IP to the internet.

Try NordVPN (NordLynx Speed) Try Surfshark (Unlimited Devices)

1. What Happens When You Tap “Connect”

Let’s walk through the connection step by step:

1. Your app chooses a VPN protocol (e.g., WireGuard, OpenVPN).
2. It performs a handshake — exchanging keys and confirming identity.
3. An encrypted tunnel is created.
4. Your device routes traffic through that tunnel.
5. Websites now see the VPN server’s IP instead of your own.

2. Encryption, Tunnels and IP Change

A VPN wraps each packet inside another encrypted packet. This is called tunnelling.

If you want the deeper cryptography side, see VPN encryption basics and VPN protocols.

3. What Your ISP Still Sees (and Doesn’t)

Your ISP can no longer see which websites you visit, but it does see:

• that you’re connected to a VPN
• the amount of data you transfer
• connection duration

Everything else — DNS requests, browsing history, IPs of sites you open — stays inside the encrypted tunnel.

4. Protocols: WireGuard, OpenVPN & IKEv2

Modern VPNs choose the fastest and safest protocol automatically. In 2025 the most common picks are:

• WireGuard / NordLynx — fastest, cleanest code, low latency
• OpenVPN — older but reliable; good for restrictive networks
• IKEv2 — mobile-friendly, quick reconnection

See also: Types of VPN Protocols.

5. DNS, WebRTC & IP Leaks

A common misconception: “VPN = perfect anonymity.” In reality, leaks happen when the system bypasses the tunnel:

• DNS leaks: your ISP’s DNS is used instead of the VPN’s resolver
• WebRTC leaks: browsers may reveal local IPs in P2P scenarios
• IPv6 leaks: some VPNs ignore IPv6, leaving gaps

A quality provider routes DNS through the tunnel and blocks WebRTC/IPv6 leaks. If your app supports a VPN kill switch, turn it on — it prevents traffic from escaping unprotected.

6. VPN vs Smart DNS vs Proxy

If your goal is streaming libraries, see VPN for Netflix and VPN for Amazon Prime.

7. Why Speeds Sometimes Drop

Speed depends on:

• server load
• distance to location
• protocol (WireGuard > OpenVPN)
• your baseline ISP connection

8. Simple Diagram: How Packets Travel

Your traffic moves like this:

1. Device → encrypted tunnel → VPN server
2. VPN server → website/app (with VPN IP)
3. Response → encrypted tunnel → your device

9. Short Video Overview

Official explanation video from NordVPN.

10. Should You Use a VPN Daily?

Short answer: Yes — if you value privacy or use public Wi-Fi.

• Home: hides browsing from your ISP
• Work cafés / hotels: protects from rogue networks
• Travel: avoids geo-restrictions
• Streaming: stable access to libraries

11. Recommended VPNs (2025)

NordVPN — Best All-Round Surfshark — Unlimited Devices

Related Guides

• VPN Encryption Basics
• VPN Protocols Explained
• VPN Kill Switch
• VPN for Remote Access
• Best VPNs 2025 (Hub)

Bottom Line

A VPN encrypts your connection, masks your IP, and routes traffic through a trusted server — giving you privacy and a cleaner internet experience. For everyday use, stick with a reputable, audited service and enable the essentials: WireGuard/NordLynx + kill switch + leak protection.

Written by Denys Shchur

Founder of SmartAdvisorOnline. Explaining security and networking in clear, simple language.