Base DNS LogoBase DNS
Logo

DNS Best Practices

Security, performance, and configuration guidelines for robust DNS infrastructure

DNS Best Practices Overview

🔒

Security

DNSSEC, DoH, CAA records

⚡

Performance

TTL optimization, anycast

⚙️

Configuration

Zone management, records

📧

Email

SPF, DKIM, DMARC setup

Security Best Practices

Enable DNSSEC

Implement DNSSEC to protect against DNS spoofing and cache poisoning attacks.

Critical

Implementation Steps

  1. 1Generate DNSSEC keys for your zone
  2. 2Sign your DNS zone with the keys
  3. 3Submit DS records to your parent zone
  4. 4Monitor DNSSEC validation status

Benefits

  • Prevents DNS cache poisoning
  • Ensures data integrity
  • Builds user trust

Use CAA Records

Control which Certificate Authorities can issue SSL certificates for your domain.

High

Implementation Steps

  1. 1Add CAA records for approved CAs
  2. 2Include issue and issuewild properties
  3. 3Set up incident reporting (iodef)
  4. 4Regularly review and update CAA records

Benefits

  • Prevents unauthorized SSL certificates
  • Enhances domain security
  • Compliance with security standards

Implement DNS over HTTPS (DoH)

Encrypt DNS queries to prevent eavesdropping and manipulation.

Medium

Implementation Steps

  1. 1Configure DoH endpoints
  2. 2Update client configurations
  3. 3Test DoH functionality
  4. 4Monitor DoH usage and performance

Benefits

  • Encrypts DNS traffic
  • Prevents ISP monitoring
  • Improves privacy

Regular Security Audits

Regularly audit DNS configurations and monitor for security issues.

High

Implementation Steps

  1. 1Schedule periodic DNS security reviews
  2. 2Monitor for suspicious DNS activity
  3. 3Review access controls and permissions
  4. 4Update DNS software and patches

Benefits

  • Early threat detection
  • Maintains security posture
  • Compliance requirements

Performance Optimization

Optimize TTL Values

Balance between caching efficiency and change flexibility.

Recommended TTL Values:

  • A/AAAA records 300-3600 seconds (stable IPs)
  • CNAME records 300-1800 seconds
  • MX records 3600-86400 seconds
  • NS records 86400-604800 seconds
  • TXT records 300-3600 seconds (depending on use)

Pro Tips:

  • 💡Use shorter TTLs during migrations
  • 💡Longer TTLs for stable infrastructure
  • 💡Consider caching implications globally

Minimize DNS Lookups

Reduce the number of DNS queries required for your services.

Strategies:

  • •Use A records instead of CNAME chains
  • •Limit CNAME depth to 2-3 levels maximum
  • •Consolidate services on fewer domains
  • •Use wildcard records where appropriate

Benefits:

  • Faster page load times
  • Reduced DNS server load
  • Better user experience

Use Anycast DNS

Deploy DNS servers globally using anycast for improved performance.

Advantages:

  • •Reduces latency by serving from nearest location
  • •Provides automatic failover capabilities
  • •Distributes query load across multiple servers
  • •Improves DNS resolution speed globally

Monitor DNS Performance

Continuously monitor DNS resolution times and availability.

Key Metrics:

  • •Query response times
  • •DNS server availability
  • •Geographic performance variations
  • •Cache hit rates

Configuration Best Practices

Zone File Management

  • Always increment SOA serial number when making changes
  • Use descriptive comments in zone files
  • Maintain consistent formatting and indentation
  • Keep backups of zone files before changes
  • Use version control for zone file changes

Record Configuration

  • Always end hostnames with a dot in zone files
  • Use absolute domain names to avoid confusion
  • Avoid mixing CNAME with other record types
  • Set appropriate priorities for MX records
  • Use consistent naming conventions

Nameserver Setup

  • Use at least 2 authoritative nameservers
  • Place nameservers in different networks/locations
  • Ensure all nameservers have identical zone data
  • Configure proper SOA refresh and retry timers
  • Test zone transfers between nameservers

Change Management

  • Test DNS changes in staging environment first
  • Plan changes during low-traffic periods
  • Reduce TTLs before major changes
  • Monitor propagation after changes
  • Have rollback procedures ready

Email Authentication Best Practices

SPF (Sender Policy Framework)

Specify which servers are authorized to send email for your domain.

Example Record:

v=spf1 include:_spf.google.com include:mailgun.org ~all

Tips:

  • •Start with ~all (soft fail) for testing
  • •Move to -all (hard fail) once validated
  • •Keep SPF records under 255 characters
  • •Avoid too many DNS lookups (max 10)

DKIM (DomainKeys Identified Mail)

Cryptographically sign emails to verify authenticity.

Setup Steps:

  1. 1Generate DKIM key pair
  2. 2Add public key to DNS TXT record
  3. 3Configure mail server with private key
  4. 4Test DKIM signature validation

Benefits:

  • Prevents email forgery
  • Improves deliverability
  • Required for DMARC

DMARC (Domain-based Message Authentication)

Coordinate SPF and DKIM to protect against email spoofing.

Policy Example:

v=DMARC1; p=quarantine; rua=mailto:[email protected]

Implementation:

  1. 1Start with p=none for monitoring
  2. 2Analyze DMARC reports
  3. 3Gradually move to p=quarantine then p=reject
  4. 4Set up aggregate and forensic reporting

MX Record Configuration

Properly configure mail exchange records for reliable email delivery.

Guidelines:

  • •Use multiple MX records for redundancy
  • •Set appropriate priority values (lower = higher priority)
  • •Point MX records to A records, not CNAME
  • •Ensure reverse DNS (PTR) records are configured

DNS Security Checklist

Security Essentials

Email Authentication

Validate Your DNS Configuration

Use our comprehensive DNS tools to verify your configuration follows these best practices.

🔍 Basic DNS Lookup🛠️ Advanced DNS Tools