Module 2

Module 2: DNS Security — Protecting the Digital Backbone

⏱ 3 min read

dnssecurityoverview

Module 2: DNS Security

DNS is the protocol everyone depends on and almost no one secures properly. It was designed in 1983 for a 1,000-node internet where everyone knew each other. Today it routes queries for billions of devices across a network that's hostile by default.

This module covers how DNS gets attacked — specifically, mechanically, with real incidents — and how to defend against it. Not theory. Production knowledge.

What You'll Learn

By the end of this module, you'll know:

  • The DNS threat surface: which attacks are common, which are rare, and why attackers care about DNS at all
  • How amplification attacks work, and why open resolvers are public infrastructure for DDoS criminals
  • The Kaminsky cache poisoning attack — one of the most elegant exploits in internet history
  • How domains get stolen (spoiler: usually through the registrar, not the protocol)
  • DNSSEC, how it works, why adoption is still low, and when you actually need it
  • DNS over HTTPS and DNS over TLS — the privacy trade-offs no one talks about honestly
  • A production-ready checklist for securing DNS infrastructure
  • Four case studies from real incidents, analyzed technically

Lessons

#TopicDuration
01DNS Security Landscape10 min
02Amplification and DDoS12 min
03Cache Poisoning and Spoofing12 min
04Domain Hijacking11 min
05DNSSEC14 min
06DNS over HTTPS and DoT10 min
07Best Practices10 min
08Case Studies15 min

Prerequisites

You should have completed Module 1, or have a solid understanding of DNS fundamentals: how resolution works, what a resolver does, the difference between authoritative and recursive DNS, and the basics of record types.

If you can explain what happens when you type a domain into a browser without consulting notes, you're ready.