DNS over HTTPS FAQ

This document answers common questions about DNS over HTTPS.

Basic Questions

What is DNS over HTTPS?

DNS over HTTPS (DoH) is a method of performing DNS queries using the HTTPS protocol. It uses encrypted HTTPS connections to protect DNS queries and responses, providing better privacy and security.

Why should I use DoH?

The main reasons to use DoH are:

  1. Privacy protection: Prevents network operators and intermediaries from viewing your DNS queries
  2. Enhanced security: Prevents DNS hijacking and man-in-the-middle attacks
  3. Avoid censorship: Prevents DNS queries from being filtered or tampered with

What’s the difference between DoH and DoT?

  • DoH (DNS over HTTPS) uses the HTTPS protocol
  • DoT (DNS over TLS) uses the TLS protocol
  • DoH is easier to pass through firewalls (uses port 443)
  • DoT uses a dedicated port 853

Technical Questions

Does DoH affect network speed?

Usually not significantly, because:

  1. HTTPS connections can be reused
  2. Modern networks have low latency
  3. Local caching can be used
  4. Nearby DoH servers can be chosen

How can I verify if DoH is working?

You can verify through these methods:

  1. Use browser developer tools to check DNS queries
  2. Use online DNS query tools
  3. Check if network connections use HTTPS
  4. Use dedicated DoH testing tools

Do all applications support DoH?

Not all applications directly support DoH, but you can work around this by:

  1. Using system-level DoH support
  2. Using proxy tools
  3. Using DNS clients that support DoH

Configuration Questions

How do I choose a DoH server?

Consider these factors when choosing a DoH server:

  1. Geographic location (choose nearby servers)
  2. Privacy policy
  3. Performance and reliability
  4. Additional features (filtering, logging, etc.)

How do I resolve DoH connection issues?

Common solutions:

  1. Check network connectivity
  2. Verify DNS server address
  3. Check firewall settings
  4. Try different DoH servers

How do I configure system-level DoH?

Configuration methods vary by system:

  • Windows: Through network settings
  • macOS: Through system preferences
  • Linux: Through systemd-resolved
  • Mobile devices: Through system settings

Security and Privacy Questions

Is DoH completely secure?

DoH provides basic security protection, but there are still considerations:

  1. Choose trusted DoH servers
  2. Consider using DNSSEC
  3. Be aware of DNS leaks
  4. Regularly update software

Does using DoH affect privacy?

DoH actually improves privacy protection:

  1. Encrypts DNS queries
  2. Prevents network operator monitoring
  3. Avoids DNS query logging
  4. Supports ESNI

Using DoH in Enterprise Environments

When using DoH in enterprise environments, consider:

  1. Network policies
  2. Security requirements
  3. Monitoring needs
  4. Compliance requirements

Next Steps