Translates domain names to IP addresses.
DNS is the internet's distributed phonebook, resolving names to IP addresses through resolvers, root, TLD and authoritative servers with caching (TTL). Record types: A, AAAA, CNAME, MX, TXT. Security: DNSSEC, DoH. Failures make sites unreachable even if servers are up.
example.com resolves to an IP address before the browser connects.
DNS lets people use names instead of numbers, and most failures that look like connection problems are actually DNS problems.
Translates domain names to IP addresses.
DNS lets people use names instead of numbers, and most failures that look like connection problems are actually DNS problems.
It translates a domain name into an IP address by querying a hierarchy of name servers.
A temporary store of answers that avoids repeated lookups, which speeds up access but can keep old records until they expire.
Typical applications include checking why a website name does not resolve on a laptop, setting up internal names for servers in a company network and changing a service's address without changing the name users type.
Study "TCP and UDP" first (topic 68 of 104 in Software & Computing). It covers the groundwork this topic builds on.
Recursive vs authoritative. Caching. Zone files.
example.com resolves to an IP address before the browser connects.
The next topic is "HTTP and HTTPS", which builds directly on this one.
It is classed as Intermediate in Software & Computing (topic 69 of 104). It is an intermediate topic. Work through the beginner topics in Software & Computing first.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.