Why do we need Name Servers?
Every time you browse the Internet, send an email, or chat online, you rely on a system that translates user-friendly domain names like “www.google.com” into numeric IP addresses that computers can understand. The service doing this essential work is known as a name server. This article will delve into what name servers are, how they work, and why they are vital to the functionality of the Internet.
What are Name Servers?
A name server is a server on the Internet specialized in handling queries regarding the location of a domain name’s various services. In essence, name servers are like internet ‘phone books.’ They maintain a directory of domain names and translate them into Internet Protocol (IP) addresses. This is necessary because while domain names are easy for people to remember, computers or machines access websites based on IP addresses.
The Domain Name System (DNS)
To fully understand name servers, having some background in the Domain Name System (DNS) is essential. The DNS is a hierarchical and decentralized naming system for computers, services, or any resources connected to the Internet or a private network. Its primary function is translating memorizable domain names to numerical IP addresses for locating and identifying computer services and devices.
DNS functions like a telephone directory, allowing users to type in a name, such as “www.example.com”, and be directed to the correct website. This process is significantly more user-friendly than remembering and typing in an IP address, which could look like “192.0.2.1”.
How Name Servers Work
Let’s now examine how name servers work within the DNS system.
When you type a domain name into your web browser, the browser first retrieves the IP address for that website from a DNS server. Here’s a step-by-step look at that process:
- Recursive Query: Your web browser (the DNS client) sends a request to a DNS server. This request is often called a recursive query. The DNS server is typically operated by your Internet Service Provider (ISP) or an independent DNS provider like Google DNS or OpenDNS.
- Iterative Query: If the DNS server does not have the IP address for the domain in its cache, it then sends a request, known as an iterative query, to one of the root name servers. The root server responds with a delegation, which points to the TLD (Top Level Domain) name server (e.g., “.com” or “.org”).
- Referral: The DNS server then sends a query to the TLD name server, which sends a referral to the authoritative name server for the specific domain.
- Final Answer: Finally, the DNS server sends a query to the authoritative name server, which responds with the IP address of the domain. This IP address is then returned to the client (your web browser), who can then request the IP address to access the website.
Types of Name Servers
Two primary types of name servers facilitate the DNS system:
- Recursive Name Servers: Also called DNS resolvers, these servers receive queries from client machines through applications such as web browsers. If they have the result of the domain name query in their cache, they respond with the answer. If not, they pass the query to another server (usually an authoritative name server) or use their resolver to traverse the DNS architecture from root servers down to the correct authoritative name server.
- Authoritative Name Servers: These servers hold the DNS records (zone files) for specific domain names. Each domain will have at least one authoritative name server which can provide an authoritative answer to a recursive server’s queries. These servers are the final authority on which IP address corresponds to which domain name.
Importance of Name Servers
The importance of name servers cannot be understated. They provide the crucial service of resolving domain names into IP addresses and vice versa, allowing users to use memorable domain names rather than cumbersome IP addresses. Without name servers, users must remember each IP address of the web services they want to access—a daunting and impractical task.
Furthermore, name servers make the Internet scalable. As the number of internet users and websites grows, name servers manage this growth effectively, ensuring users can access websites reliably.
Conclusion
Name servers are the invisible engines that drive the Internet, making it a user-friendly space where memorable domain names replace complex IP addresses. They facilitate the Internet’s speed, efficiency, and scalability, making it possible for users to access billions of Internet resources simply by remembering easy-to-use domain names. Without name servers, the Internet as we know it would not exist.