# DNS Security: Protecting Your Network Foundation
DNS translates human-readable names to IP addresses. Every internet connection starts with DNS lookup. This foundational role makes DNS an attractive attack target. Compromise DNS and you control where traffic flows.
Attackers exploit DNS in multiple ways. DNS hijacking redirects users to malicious sites. DNS tunnelling exfiltrates data through encoded queries. DDoS attacks against DNS deny service. Cache poisoning corrupts resolver responses.
Securing DNS requires understanding threats and implementing appropriate controls.
## DNS Threat Landscape
Attacks against DNS take several forms.
**DNS hijacking** redirects resolution. Attackers modify DNS responses to point to attacker-controlled servers. Victims think they reached legitimate sites. Credentials harvested. Malware delivered.
**DNS tunnelling** abuses the protocol. Data encodes in DNS queries and responses. Firewalls permitting DNS let tunnelled traffic pass. Command and control channels hide in plain sight.
**DDoS attacks** overwhelm DNS infrastructure. Amplification attacks leverage DNS response sizes. Legitimate queries fail. Services become unreachable.
**Cache poisoning** corrupts resolver caches. Attackers inject false records. Subsequent queries return attacker-controlled addresses. Effects persist until cache expires.
## Defensive Measures
Multiple layers protect DNS infrastructure.
**DNSSEC** validates response authenticity. Cryptographic signatures chain from root to response. Resolvers verify signatures. Prevents cache poisoning and hijacking of signed zones.
**DNS over HTTPS (DoH)** and **DNS over TLS (DoT)** encrypt queries. Prevents eavesdropping on DNS traffic. Obscures browsing patterns from network observers.
**DNS filtering** blocks malicious domains. Threat intelligence identifies known bad domains. Queries to malicious destinations fail. Malware cannot reach command and control.
**Logging and monitoring** detect anomalies. Query volume spikes suggest DDoS or tunnelling. Unusual query patterns warrant investigation. Baseline normal to identify abnormal.
**Redundancy and resilience** ensure availability. Multiple DNS servers in different locations. Rate limiting prevents resource exhaustion. Anycast distribution absorbs attack traffic.
## Implementation Considerations
DNS security requires attention to operations.
**Internal DNS** deserves protection too. Internal resolvers are attack targets. Apply same security principles internally. Split DNS separates internal and external zones.
**Vendor selection** for managed DNS matters. Evaluate security capabilities of DNS providers. Understand their DDoS protection. Verify DNSSEC support.
If your organisation needs help securing DNS infrastructure or implementing DNS security controls, contact us through our contact page.
## DNS as a Security Control Plane
DNS is one of the highest leverage controls for blocking commodity threats:
- phishing domains,
- malware command-and-control,
- and typo-squatting.
## Baseline Controls
- enforce secure recursive resolvers,
- block known bad domains,
- enable DNS logging,
- and protect authoritative zones with MFA and change control.
Treat DNS like identity: when it is compromised, everything else falls over.