What is recursive DNS? Every website on the Internet needs to have at least one authoritative DNS server. Authoritative servers are where that websites records are kept. The more authoritative DNS servers your website has, the more redundant it is. To understand exactly what recursive DNS is, let’s explain what exactly DNS is.

In order for a website to be accessed via its URL, i.e. www.noip.com, the website needs DNS. The Domain Name System performs like a phone book. If not for DNS you would need to know the phone number or IP address of every single website. DNS acts like a phone book by pointing a URL to the websites IP address for you. This means you don’t have to know the IP address of every website. How frustrating would that be? I can barely even remember my own phone number, let alone the phone number of every single website that I want to visit.

Anyway, the place where the phone numbers of the websites are kept are the authoritative DNS servers. Each website has at least one and if you want the website to be fully redundant, (meaning if one server has issues or downtime, your website will not be affected) they often have more – that are all located in geographically redundant locations. When you type www.noip.com into your browser, your computer queries the recursive DNS provider. If the recursive DNS server has the answer cached, then it gives that answer if it doesn’t have the answer cached, the recursive DNS server then queries the authoritative DNS server. The authoritative DNS server returns the correct answer and the website is loaded.

Although it sounds quite confusing and time-consuming, all of this happens in milliseconds. Questions or comments? Leave them in the comments! Also, click Like to share this with your friends!