DNS
Last updated
Last updated
DNS (Domain Name System) is a system that translates human-readable domain names (like example.com) into computer-readable IP addresses. When you enter a URL, DNS converts it into an IP address so the browser can locate the server. Since IP addresses are difficult to remember, DNS makes internet navigation easier.
DNS is a hierarchical, decentralized distributed database. It’s designed to store mappings between domain names and IP addresses across many servers rather than one central location. This distribution ensures scalability, fault tolerance, and performance, as different DNS servers handle queries for different parts of the domain name space.
Key components include:
Numerous DNS servers worldwide.
13 root server clusters (with over 1,000 actual servers) to handle top-level queries.
Hundreds of generic top-level domains (gTLDs), like .com or .org.
Over 275 country code top-level domains (ccTLDs), like .uk or .jp.
Note: The 13 root server clusters are responsible for directing DNS queries to the appropriate top-level domain (TLD) name servers. These clusters are geographically distributed with over 1,000 actual servers to ensure global coverage and reliability. Root servers handle the initial step of the DNS resolution process: when a domain is queried, the root server directs the query to the appropriate TLD server (e.g., .com or .org).
Formation: Root servers are managed by different organizations and are redundantly spread across the globe to ensure resilience and prevent failure from impacting DNS resolution globally.
DNS (Domain Name System) is crucial for translating human-readable domain names into IP addresses, enabling:
Name Resolution: Converting domain names (e.g., example.com) to IP addresses so that web browsers and other services can locate and connect to the correct servers.
Web Access: Facilitating access to websites by resolving domain names to their corresponding IP addresses.
Active Directory Resolution: Supporting the lookup of directory services in networks, particularly in Windows environments, for authentication and resource management.
Application Access: Allowing applications to connect to servers and services using domain names instead of IP addresses.
Redundant DNS Servers ensure reliability and availability by providing backup servers that can take over if the primary DNS server fails, minimizing downtime and maintaining continuous access.
