Blocking Adult Content at the Proxy Layer: Mandatory HTTPS Enforcement, Category Filtering, and Always-On VPN

Summary

DNS-based adult content filtering is the most commonly recommended approach and the least reliable technically. Here is why it fails and how to implement proxy-layer filtering that cannot be bypassed with a DNS settings change. Why DNS filtering fails for adult content blocking DNS filtering intercepts name resolution queries and returns NXDOMAIN for blocked domains. Three bypass vectors make it unreliable: 1. Manual DNS override (30 seconds, no technical knowledge required): ...