2026-02-04 · Head of Security

Why DNS Security Is the New Perimeter

A technical primer on why DoH, DoT, and RPZ are the foundation of modern infrastructure security.

For decades, perimeter security meant firewalls. In a cloud-first, edge-first, BYOD world, that perimeter no longer exists in any meaningful sense.

The new perimeter is the resolver. Every request — every malware callback, every phishing redirect, every tracker — passes through DNS.

Three technologies make resolver-layer protection viable in 2025:

  1. DNS-over-HTTPS (DoH) — encrypts queries in transit
  2. DNS-over-TLS (DoT) — same protection over a dedicated port
  3. Response Policy Zones (RPZ) — programmable response filtering

Combine these and you get a control plane that filters threats before they touch your network — without inspecting endpoint traffic, without installing agents, and without the surveillance tax.