What Is Global DNS Server?
A Global DNS Server is a crucial component of the Domain Name System (DNS) infrastructure. It plays a vital role in translating human-readable domain names into machine-readable IP addresses. In simple terms, it acts as a phonebook of the internet, converting the domain names we type into our web browsers into the numerical IP addresses that computers use to communicate with each other.
The Function of Global DNS Servers
Global DNS servers are responsible for storing and distributing DNS records globally. These servers work together to ensure that requests for domain name resolutions are efficiently handled.
When you enter a website URL in your browser, your computer sends a request to your Internet Service Provider’s (ISP) DNS server. If the ISP’s server doesn’t have the requested domain name mapped to an IP address in its cache, it queries other authoritative DNS servers to find the necessary information.
This is where global DNS servers come into play. They act as authoritative sources for specific domains and provide accurate information about IP addresses associated with those domains.
DNS Hierarchy and Root Servers
The DNS system is organized hierarchically, with several levels of authority. At the top of this hierarchy are thirteen Root Servers, labeled A through M, managed by various organizations around the world. These servers contain information about top-level domains (TLDs), such as .com, .org, .net, etc.
Below the root servers are TLD Name Servers. For example, if you request a website ending with .com, your ISP’s server will query one of the TLD name servers managed by Verisign or another authorized registrar for .com domains.
The Role of Global DNS Servers
Global DNS servers come into play at the next level in the hierarchy, known as Authoritative Name Servers. These servers are responsible for storing and providing information about specific domain names within a TLD.
For example, if you enter “example.com” in your browser, your ISP’s server will query one of the authoritative name servers responsible for the .com TLD. These authoritative servers will then provide the IP address associated with “example.com”.
Ensuring Efficiency and Redundancy
Global DNS servers work in tandem to ensure efficient and reliable resolution of domain names to IP addresses. They are distributed worldwide to minimize latency and improve response times.
To enhance redundancy and avoid single points of failure, there are multiple instances of global DNS servers strategically placed across different geographical locations. This redundancy ensures that if one server fails or becomes overloaded, others can take over seamlessly.
Caching and TTLs
To further enhance performance, DNS servers utilize caching. When an ISP’s server receives a response from a global DNS server, it stores the information in its cache. This reduces the time required to resolve subsequent requests for the same domain name from other users on the network.
The duration for which DNS records remain cached is determined by Time-To-Live (TTL) values set by domain owners. TTL values indicate how long a DNS record can be stored in a cache before it needs to be refreshed from an authoritative source.
Global DNS servers play a critical role in translating human-readable domain names into machine-readable IP addresses. They ensure efficient resolution of internet requests by distributing authoritative information about domain names globally. With their strategic placement and redundant architecture, global DNS servers help maintain a stable and reliable internet infrastructure.