VPN

How a VPN Works

A VPN creates an encrypted VPN TunnelAn encrypted, encapsulated connection between two endpoints through which all tunneled data passes securely across an untrusted network like the public internet. between your device and a VPN server. All your internet traffic is routed through that server, so websites see the server's Public IP AddressA globally unique IP address assigned by an ISP that is routable on the public internet. Every device directly accessible from the internet must have a public IP address. instead of yours. The data flowing through the tunnel is wrapped in an additional protocol layer — commonly IPSecInternet Protocol Security. A suite of protocols that authenticates and encrypts IP packets at the network layer. Used in site-to-site VPNs and as the transport layer for L2TP/IPSec and IKEv2 VPN connections., OpenVPNAn open-source VPN protocol that uses SSL/TLS for key exchange and can operate over UDP or TCP. Known for its flexibility, strong security, and wide platform support, though slower than WireGuard., or WireGuardA modern, lightweight VPN protocol that uses state-of-the-art cryptography (ChaCha20, Curve25519) with a minimal codebase (~4,000 lines). Designed for simplicity, high performance, and low latency compared to OpenVPN and IPSec. — making it unreadable to anyone observing the connection in transit.

Common Use Cases

Businesses use VPNs to give remote employees secure access to internal networks. Privacy-conscious individuals use them to prevent ISPInternet Service Provider. A company that provides internet access to consumers and businesses, assigning public IP addresses and routing traffic to the wider internet. Examples include Comcast, AT&T, and SK Broadband. surveillance or to bypass regional content restrictions. Security researchers use VPNs to avoid exposing their real IP during reconnaissance work.

Limitations to Understand

A VPN shifts trust from your ISP to your VPN provider — the provider can still log your activity if they choose to. A misconfigured VPN can suffer a DNS LeakA privacy flaw where DNS queries bypass the VPN tunnel and are sent to the ISP's default DNS resolver, revealing the websites a user visits despite using a VPN. DNS leak tests help detect this issue. or WebRTC LeakA privacy vulnerability where WebRTC (a browser API for real-time communication) reveals a user's real public and local IP addresses through STUN requests, even when connected to a VPN., exposing your real IP despite the tunnel being active. VPNs also add latency because traffic must travel to the VPN server before reaching the destination. Use DNS Leak Test to verify your VPN is not leaking DNS queries outside the tunnel.