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Domain Name System

DNS is a distributed, hierarchical database for converting DNS names into IP addresses.

It runs in 2 modes:

  • Recursive with caching
  • Authoritative mode

A network node will send a DNS query to a recursive caching server which will make recursive queries until it reaches an authoritative server. The authoritative server wil send the response back the tree.

The DNS database consists of a tree-like, key-value store. The database is broken into tree nodes called Domains. These domains are managed as part of a zone. Zones are the area of the namespace managed by authoritative server(s). DNS delegation is done on zone boundaries.