DNS Lookup

DNS Lookup

DNS Lookup, also known as Domain Name System Lookup, is the process of querying the Domain Name System (DNS) to translate human-readable domain names (like www.example.com) into the IP addresses that computers use to identify and communicate with each other over the internet.

When you enter a domain name into your web browser's address bar, your computer needs to know the corresponding IP address of the server hosting that website. This is where DNS Lookup comes into play. The DNS system is essentially a distributed database that maintains a mapping between domain names and their corresponding IP addresses.

Here's a simplified breakdown of how DNS Lookup works:

• User enters a domain name (e.g., www.example.com) into a browser.
• The computer first checks its local DNS cache to see if it has the IP address for that domain already stored.
• If the IP address is not found in the cache, the computer sends a DNS query to a DNS resolver (usually provided by your Internet Service Provider or a public DNS service like Google DNS or Cloudflare DNS).
• The DNS resolver then searches for the IP address associated with the domain name. It starts by checking its own cache for the mapping.
• If the mapping is not in the resolver's cache, it performs a series of iterative queries to the DNS hierarchy. It starts by querying the root DNS servers to find out the authoritative DNS server for the top-level domain (e.g., ".com").
• The resolver then queries the authoritative DNS server for the top-level domain, which directs it to the authoritative DNS server for the specific domain (e.g., "example.com").
• Finally, the authoritative DNS server provides the IP address for the requested domain back to the resolver, which then stores the mapping in its cache and returns the IP address to the user's computer.
• The user's computer now has the IP address and can establish a connection with the web server hosting the requested website.

This process is essential for the proper functioning of the internet, as it enables users to access websites using easy-to-remember domain names, while computers communicate with each other using numerical IP addresses. DNS Lookup happens transparently in the background whenever you browse the web or use any network-connected application.