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Protecting DNS Infrastructure: The Attack Vector That Takes Down Everything

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Akarguard Team

Security Engineering

Sep 13, 20268 min read

If your DNS goes down, your entire infrastructure is unreachable — regardless of how well-protected your servers are. DNS is the forgotten attack surface.

It is possible to have perfectly protected, fully operational servers and still be completely offline — if your DNS goes down. The 2016 Dyn attack proved it: Twitter, Netflix and Reddit did not fall because their own servers were overwhelmed, but because the DNS provider that translated their names into addresses was. DNS is the foundation everything else stands on, and it is routinely the least protected layer in the stack.

The Kinds of DNS Attack

  • Query floods: millions of DNS queries per second aimed at your authoritative nameservers to exhaust them.
  • NXDOMAIN floods: queries for names that do not exist, forcing expensive negative lookups.
  • DNS amplification: abusing your resolver as a reflector to attack someone else (and consuming your capacity in the process).
  • Phantom-domain attacks: flooding a resolver with queries to slow or non-responding domains so it ties up resources waiting.

Why DNS Is So Exposed

DNS runs mostly over UDP, which is stateless and trivially spoofable, so an attacker can forge source addresses and a server cannot easily tell a real query from a hostile one. Authoritative servers are generally sized for normal query load, not attack-scale volume. And because DNS is on the critical path for every single request, even partial degradation — a bit of added latency — shows up immediately as user-visible failures across everything you run.

DNS is a separate defence problem

Protecting your website does not protect your DNS, and vice versa. They are different services on different infrastructure. A resilient stack defends both — and many teams remember the web tier and forget the name tier until the day it takes everything down.

Hardening Your DNS

  • Use a DDoS-resistant DNS provider with a distributed, high-capacity anycast nameserver network.
  • Implement Response Rate Limiting (RRL) on authoritative nameservers to blunt amplification abuse.
  • Run at least four geographically distributed authoritative nameservers so no single one is a choke point.
  • Keep TTLs sensible so resolvers cache answers and absorb some load for you.

Where Akarguard Fits — and Where It Doesn't

Be clear on scope: Akarguard protects your website's HTTP/HTTPS traffic, not your authoritative DNS. For DNS-layer floods, the defence is a DDoS-resistant DNS provider as above — that is a different service. What Akarguard does add is origin privacy: once your web traffic resolves to the Akarguard edge, your real server IP stays hidden, which removes one of the ways attackers discover and directly target the infrastructure behind your DNS. Protect the name layer with a hardened DNS provider and the web layer with a reverse proxy; together they close the gap.

Frequently asked questions

What happens if my DNS is DDoSed?

Your entire infrastructure becomes unreachable, no matter how well your servers are protected, because clients cannot resolve your name into an address. The 2016 Dyn attack took major sites offline this way — the servers were fine, but their DNS provider was overwhelmed.

Why is DNS vulnerable to DDoS?

DNS runs mostly over UDP, which is stateless and easy to spoof, so servers struggle to tell real queries from hostile ones. Authoritative servers are sized for normal load, and because DNS is on the critical path for every request, even small degradation causes immediate, widespread failures.

How do I protect my DNS from DDoS?

Use a DDoS-resistant DNS provider with a distributed, high-capacity anycast network, enable Response Rate Limiting on authoritative servers, run at least four geographically distributed nameservers, and keep TTLs sensible so resolvers absorb some load. DNS is a separate defence problem from your web tier.

Does Akarguard protect DNS?

No — Akarguard protects your website's HTTP/HTTPS traffic, not your authoritative DNS; use a DDoS-resistant DNS provider for that. What it adds is origin privacy: your web traffic resolves to the Akarguard edge, so your real server IP stays hidden, removing one way attackers find and target your infrastructure.

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Akarguard Team

Security Engineering at Akarguard

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