Interview Bootcamp
Vote

0% completed

​

DNS Resolution Process

DNS resolution is the process of converting a domain name into its IP address. Two things make it fast enough to be invisible: the way queries are asked, and the caching that stops most of them from travelling far.

Two Ways to Ask

A DNS query comes in two styles, and the difference is about who is responsible for finding the answer.

Recursive query

The resolver asks the server for the complete answer.

If the server has it, it replies. If it does not, the server takes on the job of contacting other DNS servers until it finds the answer, and only then replies

.....

.....

.....

Like the course? Get enrolled and start learning!
Ricardo Franco

Ricardo Franco

· 3 years ago

Who decides when to use recursive or iterative queries?

Ricardo Franco

Ricardo Franco

· 3 years ago

Negative caching is the process of caching the non-existence of a DNS record. When a resolver receives a query for a non-existent domain or record, it caches this information as a negative response, preventing repeated queries for the same non-existent resource. This reduces the load on DNS servers and improves overall performance.

How a resolver can prevent a query from arriving on it?

I think the resolver uses negative caching to prevent querying DNS servers for non-existent domains. In this case, the text should be "When a resolver receives a response for a non-existent domain". Am I correct?

Show 2 replies