Networking
What is DNS?
Domain Name System — translates human-readable domain names into IP addresses.
The Domain Name System (DNS) is the internet's phonebook. It translates human-readable domain names like testrefy.com into machine-readable IP addresses like 192.0.2.1 that computers use to communicate.
DNS is hierarchical and distributed across millions of servers worldwide. This redundancy makes it resilient but means changes can take up to 48 hours to propagate globally (controlled by TTL settings).
Key DNS Record Types
- A: Maps domain to IPv4 address
- AAAA: Maps domain to IPv6 address
- CNAME: Alias to another domain
- MX: Mail server for the domain
- TXT: Verification and SPF/DKIM records
- NS: Authoritative name servers
FAQ
How long does DNS propagation take?
DNS changes typically propagate within 1-4 hours but can take up to 48 hours globally, depending on the TTL (Time to Live) value set on the record.
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