Currently, requesting a website seems the easiest thing for users, no matter their geographical location. But the process for this task to be successfully executed is complex. Many actors get involved in the Domain Name System (DNS) scene for users in the world to navigate the Internet easily. Today, we are introducing Recursive DNS servers.
What do Recursive DNS Servers do?
Recursive DNS servers, also called DNS resolvers, are the type of servers that get DNS queries from users and have the responsibility of resolving them by searching for the necessary DNS records in the DNS namespace.
Recursive DNS servers are an important part of the Internet infrastructure (DNS) because, thanks to their collaboration, the translation of domain names (human language) into numerical IP addresses (machine language) gets possible and in an agile way.
How do Recursive DNS Servers work?
Every time you, and users around the globe, request a domain through your browser, a Recursive DNS server starts working. It gets your DNS request, and then it starts searching for its associated IP address. To get this DNS record, a Recursive DNS server has two options. The first is it will look for it within its cache. If the TTL (time-to-live) has not expired, it will be there. So the Recursive DNS server will accomplish its mission fast. It is important to know that this type of server does not store DNS data permanently, only the time that the DNS records are valid, and every network administrator establishes this time. Different factors intervene to define a lower or higher value (time) for DNS records’ TTL. Once this time expires, data has to be gotten again (refreshed).
If the IP address is not present anymore within the cache of the Recursive, it will walk a different and longer path to get it. The Recursive DNS server will start a deeper search by querying several other DNS servers until it reaches the exact Authoritative name server that holds the DNS record. This repetitive process is known as recursion. In this computing science context, it is a solving problem method that means a program will call itself repeatedly until a condition is met. Now, you can understand the reason behind these servers’ name.
When the Recursive DNS server gets the IP address, the last step is to give it to you (the user). Only if the DNS record is successfully found and delivered will you load the domain name you requested. Different issues can happen. So in some unsuccessful cases, it can be determined that the domain name you requested can’t be resolved.
Recursive DNS servers work very fast. It certainly takes much longer to explain the process than for them to execute it!
Now, you know Recursive DNS servers, how they work and what they do. They are DNS actors that work non-stop. They are essential for users to reach your domain and for you to get profits!