What is DNS and How Does It Work? (The Internet's Phonebook)

DNS is the internet’s phonebook. It turns human‑readable names (like checkmyipaddress.xyz) into IP addresses. A fast, private DNS setup improves speed, privacy, and reliability.

Level 1: How DNS Works

1. Your device asks a resolver (ISP default or custom like 1.1.1.1 / 8.8.8.8).
2. The resolver queries authoritative name servers (root → TLD → domain).
3. The answer is cached and returned, speeding up future lookups via TTL.

Common Record Types

• A/AAAA — IPv4/IPv6 addresses
• CNAME — Alias one name to another
• MX — Mail exchangers
• TXT — Metadata (SPF/DKIM/verification)
• NS — Delegation pointers

Level 2: Security and Privacy

DNSSEC

DNSSEC adds cryptographic signatures to protect against spoofing. It verifies that DNS answers haven’t been tampered with.

Encrypted DNS

• DoH (DNS over HTTPS) — DNS queries inside HTTPS; easy to deploy on modern devices.
• DoT (DNS over TLS) — Dedicated TLS for DNS; common on routers and Android.

Level 3: Improve Speed and Privacy

Choosing a Resolver

• Cloudflare — 1.1.1.1 (fast, privacy‑focused; malware blocking at 1.1.1.2)
• Google — 8.8.8.8 (reliable, global anycast)
• Quad9 — 9.9.9.9 (malware/phishing blocklists)

How to Change Your DNS

1. Router: Set DNS servers in WAN/Internet settings → applies to your whole network.
2. Device: Set DNS in Wi‑Fi/Ethernet adapter settings for per‑device control.
3. Browser: Enable DoH in settings (Firefox/Chrome/Edge) for in‑browser encryption.

Troubleshooting

• Flush caches: OS/browser/resolver after changes.
• Check for captive portals on public Wi‑Fi that block DoH/DoT.
• Verify DNSSEC and query path with tools like nslookup/dig.

Conclusion

Switching to a fast, privacy‑respecting resolver and enabling DoH/DoT is a quick win for speed and security. Consider DNSSEC where supported for tamper‑resistant answers.