How the Internet Finds a Website

Before a browser loads a website, it must resolve the hostname. DNS is the step that answers where the browser should connect.

Key points

• Browser asks operating system or configured resolver.
• Resolver returns A or AAAA records, sometimes after following CNAME records.
• Browser connects to the IP address.
• TLS and HTTP happen after DNS.

Where dig fits

Dig is useful because it lets you ask DNS one precise question at a time. Instead of guessing why a website, email system, or service is failing, you can check the record type that controls that part of the setup.

Practical next step

Start with the record type that matches the symptom. Use A or AAAA for website address issues, MX and TXT for email, CNAME for provider aliases, and NS or SOA for delegation problems.