DNS RESOLVER

A DNS resolver works like a cache memory that helps the operating system find the IP address of a domain name by communicating with different DNS servers.

How the Process Works

1. Let’s say you enter a domain like example.com.
2. First the request goes from the client to the operating system.
3. The operating system then asks the DNS resolver if it already knows the IP address for that domain.
4. If the resolver has the answer stored in its cache, it immediately returns the IP address. This makes the process very fast.
5. If the resolver does not have the IP address, it starts querying other DNS servers step by step.
6. It begins with the root server, then moves to the top-level domain server, and finally reaches the authoritative DNS server, which holds the actual IP address.
7. Once the resolver gets the IP address, it stores it in its cache for future use and then sends it back to the operating system.

What Happens Next Time

1. When the same request is made again, the operating system first checks with the resolver.
2. If the resolver already has the IP in its cache, it returns the result instantly without going through the full process again.
3. This reduces the time taken and improves performance.

Workflow Summary