VPN and Network Connections

How VPNs work, why they get blocked, and methods to bypass restrictions.

Published December 31, 2025 ET
technologynetworkingsecurity

How VPN Connections Work

  • TODO: what VPN stands for (Virtual Private Network)
  • TODO: encrypted tunnel between your device and VPN server
  • TODO: your traffic appears to come from VPN server's IP

The Technical Process

  • TODO: handshake and authentication
  • TODO: encryption protocols (OpenVPN, WireGuard, IKEv2)
  • TODO: how packets are encapsulated

How Database Connections Work

  • TODO: similar concept of establishing secure tunnel
  • TODO: TCP/IP connections
  • TODO: SSL/TLS encryption
  • TODO: connection pooling

Why VPNs Get Blocked

Deep Packet Inspection (DPI)

  • Network firewalls can analyze packet contents
  • TODO: how DPI identifies VPN traffic patterns
  • TODO: OpenVPN signatures vs obfuscated protocols

IP Blacklisting

  • TODO: known VPN server IPs get blocked
  • TODO: how services maintain blacklists

Port Blocking

  • TODO: common VPN ports (1194 for OpenVPN, 51820 for WireGuard)
  • TODO: blocking non-standard ports

The Tinker Street Tavern Problem

  • Some networks block VPN connections entirely
  • TODO: corporate/venue WiFi restrictions
  • TODO: why establishments do this

Bypass Methods

Using a Remote Server

  • TODO: SSH tunneling
  • TODO: setting up your own VPN on a VPS
  • TODO: but what if connections to those are also blocked?

Obfuscation Techniques

  • TODO: Shadowsocks
  • TODO: obfsproxy
  • TODO: making VPN traffic look like regular HTTPS

Alternative Ports

  • TODO: running VPN over port 443 (HTTPS)
  • TODO: running over port 53 (DNS)

Other Approaches

  • TODO: Tor network
  • TODO: meek pluggable transport
  • TODO: domain fronting

References