Understanding DNS (Domain Name System)

Domain Name System (DNS) Overview

• Translates human-readable domain names into IP addresses, allowing users to access websites easily.
• Operates as a hierarchical system managing network addresses and enabling resource identification.

Purpose of DNS Servers

• Acts as intermediaries that facilitate the retrieval of website data by translating domain names into corresponding IP addresses.
• Enables devices to connect to web servers hosting specific resources.

User Accessibility and IP Addresses

• Users typically do not need to remember numeric IP addresses; they can use easily remembered domain names instead.
• Makes internet navigation user-friendly and accessible by simplifying how users think of website locations.

Role of DNS Servers

• Essential in resolving web addresses by retrieving the correct IP addresses from a database of stored information.

Role of DNS Recursor

• Functions as the first point of contact during a DNS query, taking the request from a user and initiating the query process to find the relevant IP address.
• Conducts the necessary queries against various DNS servers to retrieve the final IP address.

Function of Top-Level Domain (TLD) Nameservers

• Responsible for directing queries to the appropriate authoritative nameservers based on the domain extension (e.g., .com, .org).
• Acts as the first layer in the DNS resolution process to facilitate finding the target domain's nameserver.

Master Server vs. Slave Server

• Master servers hold the primary DNS records and can make changes to them, whereas slave servers replicate data from master servers to ensure redundancy.
• Slave servers provide backup and load distribution for nameserver queries.

Primary Role of Recursive DNS Servers

• Manages all aspects of DNS query resolution by searching for the correct IP address through the entire DNS hierarchy.
• Reduces the need for user devices to contact multiple servers directly, streamlining the process.

Authoritative DNS Servers vs. Recursive DNS Servers

• Authoritative servers store the actual DNS records for domains and respond directly to queries about those specific records.
• Recursive servers do not store records but query other servers to locate the correct data, functioning more as a facilitator of the resolution process.