What Is DNS Server and Why It Is Used?
The Domain Name System (DNS) is an integral part of the internet that converts human-readable domain names into IP addresses. In simpler terms, it acts as a phonebook for the internet, translating domain names like www.example.com into their corresponding IP addresses, such as 192.168.0.1.
How Does DNS Work?
When you enter a URL in your web browser, your computer needs to know the IP address of the website’s server to establish a connection. Instead of memorizing complex strings of numbers, we use domain names for ease of use.
Here’s how DNS works:
- Requesting a URL: When you enter a URL, your computer sends a request to a DNS resolver (usually provided by your ISP).
- DNS Lookup: The resolver checks its local cache for the corresponding IP address. If it finds a match, it returns the result immediately.
- Recursive Search: If there is no match in the local cache, the resolver starts a recursive search process to find the IP address.
- Root Servers: The resolver contacts root servers to find information about top-level domains (.com, .org, etc.).
- TLD Servers: The root servers direct the resolver to TLD (top-level domain) servers responsible for specific extensions (like .com).
- Name Servers: The TLD servers then point the resolver to authoritative name servers that store information about individual domains.
- DNS Response: The authoritative name server returns the IP address to the resolver.
- Caching: The resolver stores the IP address in its cache for future use, speeding up future requests to the same domain.
- Connection Established: Armed with the IP address, your computer can now establish a connection with the web server hosting the requested website.
Why Is DNS Server Used?
DNS servers are crucial for several reasons:
- Human-Readable Naming: As mentioned earlier, DNS allows us to use easy-to-remember domain names instead of remembering complex IP addresses.
- Faster Browsing Experience: By caching IP addresses, DNS resolvers can quickly retrieve information without performing lengthy searches, resulting in faster browsing speeds.
- Load Balancing: Websites often have multiple servers to handle high traffic. DNS servers can distribute incoming requests among these servers, ensuring efficient load balancing and preventing overload on a single server.
- Fault Tolerance and Redundancy: If one DNS server goes down, others can still handle requests, ensuring that websites remain accessible even during server failures.
- Email Delivery: DNS is also used for email delivery. It helps route emails by translating domain names in email addresses into their respective mail servers’ IP addresses.
The Domain Name System (DNS) plays a pivotal role in internet communication by translating domain names into IP addresses. By simplifying web browsing and improving efficiency, DNS servers enhance our overall online experience. Understanding how they work can help us appreciate their significance and optimize our internet usage.