The Domain Name System (DNS) is a core Internet service that connects memorable names with the numerical addresses computers use to communicate. This lesson introduces DNS, its purpose, and the problem it was designed to solve.
DNS is a hierarchical, distributed naming system for computers, services, and other resources on IP networks. Its best-known function is translating a human-readable domain name, such as www.example.com, into an IP address that a computer can use to locate a service.
All flashcards
What is the Domain Name System (DNS)?
A hierarchical, distributed naming system that stores information about resources on IP networks.
What was HOSTS.TXT?
A centrally maintained ARPANET text file that mapped hostnames to numerical addresses.
What is an authoritative DNS server?
A server that provides definitive DNS information for a zone it serves.
What does DNSSEC add to DNS?
Cryptographic signatures that help validate DNS data and protect its integrity.
How does a DNS registrar differ from a registry?
A registrar provides a service for requesting domain registration; a registry operates a TLD's authoritative database.
Quiz questions
How is delegation of a child zone commonly represented in its parent zone?Answer: NS records identify the child zone's name servers.
In a recursive DNS query, what does the requesting client ask the server to do?Answer: Return a complete answer, contacting other servers if needed.
What protection does DNSSEC primarily provide for DNS data?Answer: It helps validate data integrity using cryptographic signatures.
What is the role of a registry in domain name registration?Answer: It operates the authoritative database for a top-level domain.
Which transport and port are commonly associated with DNS over TLS (DoT)?Answer: TLS over TCP port 853.
Based on the Wikipedia article Domain Name System, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.