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DNS

Networks and Connectivity

The Domain Name System (DNS) connects names such as in4byte.es to the information needed to reach a service, such as the IP address of a web server.

Synonyms: domain name system, name resolution, DNS server, domain, nameserver

Examples for small businesses

  • When someone visits www.empresa.com, their browser relies on DNS to look up the web server’s address.
  • A company adds an A record for its website, MX records for mail delivery and a TXT record for SPF.
  • When moving a website, a technician updates the records for the main domain and www to point to the new host and checks that the old and new services overlap as needed.

Common mistakes

  • Changing records without checking their time to live (TTL), which affects how long resolvers can cache them.
  • Deleting or duplicating records without checking whether another service needs them.

Related terms

FAQ

How long does it take for a DNS change to take effect?
It depends on the previous TTL and resolver caches. Some users see a change within minutes, while others may continue to receive the cached answer until it expires.
Which DNS resolver should I choose?
Cloudflare, Google, Quad9 and OpenDNS are examples. Compare their privacy, filtering and reliability requirements for your organisation.