🌐DNS

NEW

Also known as: Domain Name System

A hierarchical, distributed naming system that translates human-readable domain names into IP addresses.

DESCRIPTION

DNS maps domain names to IP addresses via a globally distributed hierarchy of servers. Resolvers query recursive and authoritative servers, following referrals from root and TLDs. DNS underpins virtually all Internet services and supports extensions like DNSSEC for integrity. Operational concerns include caching, TTLs, zone management, and mitigation of attacks such as cache poisoning and DDoS. Managed DNS providers and cloud services simplify administration and scaling.

ALTERNATIVE DEFINITIONS

IETF RFC 1034

The domain name system is a distributed database for mapping names to resources.

Foundational specification emphasizing distributed database design.

Source

ICANN

The Domain Name System (DNS) translates domain names (like example.com) into IP addresses used by computers to identify each other on the network.

Public-facing explanation tying DNS to Internet governance.

Source

Cloudflare

DNS stands for Domain Name System, the phonebook of the Internet that translates domain names to IP addresses.

Accessible analogy describing DNS’s role for end users.

Source

RELATED TERMS

Domain Name IP Address Resolver Authoritative Name Server Recursive DNS Zone File TTL DNSSEC Anycast Root Server

COMPETING TERMS

Multicast DNS Hosts File

KNOWLEDGE AREAS

Infrastructure Data Services

TARGET AUDIENCE

DevOps Engineer Cloud Architect Security Architect Application Administrator IT Manager

EXTERNAL SOURCES

• Wikipedia - Domain Name System
• IETF - Concepts and facilities of DNS
• IETF - DNS implementation and specifications
• ICANN - Overview of DNS for the public
• AWS - Managed DNS service documentation

TOP QUESTIONS

Why is DNS critical to Internet operations?

It translates human-friendly names into routable IP addresses, enabling users and applications to find services reliably.

Category: Relevancy

How does a DNS lookup work?

A resolver queries recursive servers, which consult cache or follow referrals from root to TLD and authoritative servers to resolve the domain.

Category: Example

What is the biggest misunderstanding about DNS?

That DNS is purely centralized; it’s a distributed, hierarchical system coordinated globally.

Category: Misunderstanding

How do TTLs affect DNS performance?

TTLs control caching duration, impacting propagation speed, load on authoritative servers, and responsiveness to changes.

Category: Requirements

What are common DNS security risks?

Cache poisoning, DDoS on resolvers, and misconfigured records; DNSSEC helps protect integrity.

Category: Risks

What is a competing approach to traditional DNS?

Multicast DNS resolves names on local networks; hosts files provide static mappings per machine.

Category: Alternatives

How is DNS managed in cloud environments?

Providers offer managed DNS, health checks, and traffic policies, simplifying scaling and failover.

Category: Management

What is DNSSEC?

It adds cryptographic signatures to DNS data, enabling resolvers to verify authenticity and prevent tampering.

Category: Overview

Where to start learning DNS?

Read RFC 1034/1035, ICANN resources, and vendor docs like Cloudflare and Route 53.

Category: Overview