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What Is DNSSEC, and What Does It Actually Protect Against?

DNSSEC (Domain Name System Security Extensions) adds cryptographic signatures to DNS responses, so a validating resolver can detect whether an answer was tampered with in transit — for example by a DNS cache-poisoning or spoofing attack. It does not encrypt DNS traffic and does not protect against every DNS-based attack; it protects the integrity and authenticity of the answers themselves.

Last updated August 9, 2026.

How the chain works, briefly

Your DNS host signs your zone with a key pair. The public half is published as a DNSKEY record. A hash of that key — the DS (Delegation Signer) record — is then published at your domain's parent zone (by your registrar), linking your zone's signature into the parent's. This chain continues up to the root, which is why it's called a chain of trust.

A validating resolver walks that chain from the root down. If every link verifies, it returns the answer with the authenticated-data (AD) flag set. If any link fails to verify — a mismatched DS after a key rotation is the most common cause — the resolver returns SERVFAIL rather than a possibly-forged answer, which is why a botched DNSSEC rotation can take a domain offline for everyone behind a validating resolver while it still loads fine elsewhere.

What Nivaronix checks — and what it doesn't

Nivaronix checks whether DNSSEC is enabled — specifically, whether a DS record is published at the parent zone, and whether our resolver's response carried the authenticated-data (AD) flag for that lookup. This is a presence-and-signature-status check, not full chain-of-trust validation from the root down through every intermediate zone. For an independent, full-chain validation view, use a dedicated tool such as dnsviz.net.

Enabling it, and the one rule that matters

  1. Turn on DNSSEC signing at your DNS host.
  2. Take the DS record it generates and add it to your domain at your registrar (the party that controls the parent zone delegation).
  3. Wait for propagation before relying on it, and re-check with a full-chain tool.
  4. Never remove or rotate a key without first disabling signing in the correct order — an out-of-sync DS record is the single most common cause of a DNSSEC-signed domain going dark.

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