Network Security

DNS Security

Risk: DNS poisoning and tunneling bypass security controls. Explore cache poisoning, tunneling, DoH/DoT, and DNSSEC protection.

NET-DNS-01Module ID
Hands-onLab Type
IntermediateLevel

Overview

Understand DNS trust, how poisoning works, tunneling techniques for exfiltration, and how modern protocols and DNSSEC mitigate risk.

Learning Outcomes

  • Explain recursive resolution and caching behavior
  • Demonstrate DNS cache poisoning scenarios
  • Detect and disrupt DNS tunneling patterns
  • Evaluate DoH/DoT visibility trade-offs
  • Validate zones and records with DNSSEC

Hands-on Labs

Run controlled poisoning attempts, generate tunneled traffic, test policy controls, and enable DNSSEC validation.

Defenses

Harden resolvers, restrict egress, monitor anomalies, and implement DNSSEC with alerting.