DNS is the keystone for the Internet to work. And it sounds simpler than it actually is! DNS is a massive infrastructure integrated by different components in charge of many processes. We could go long just talking about servers because not all of them comply with the same functions. They are different!
Let’s dig into the Authoritative DNS server meaning!
What does an Authoritative DNS server mean?
Authority is explicitly stated in this server’s name. The Authoritative DNS server is the authority for its corresponding zone. It stores the original zone records, important DNS data related to domains.
It provides answers to users’ requests only for its corresponding zone, the one it got configured to cover. The data it stores is not cached but directly saved in its system. Due to the essential data it holds, it’s the last and crucial step during the DNS resolution process. This means it receives and answers other servers’ requests.
Let’s think a user wants to visit a domain. He or she types the domain name and requests it through the browser. This DNS request is sent to his or her Internet service provider (ISP), for one of its different recursive servers to answer it with the IP address of the requested domain. A recursive server can search the IP address in its cache memory. Recursive servers had within their functionality to cache DNS data during a specific period of time. If this choice doesn’t succeed, the recursive has to ask different servers until it reaches the authoritative DNS server. This last is the one that can provide the correct IP address for the requested domain to be loaded and visited by the user.
Authoritative DNS servers are essential for the DNS to operate. They have a database of domain names and their corresponding IP addresses. They are the only ones that can supply updated DNS data for the DNS resolution process to be successfully completed. They are meant to manage the master zone. Since they don’t hold copies but the original zone file that stores the DNS records, any modification, addition, removal, etc., can be made only from them.
Types of Authoritative DNS servers.
There are two different types of Authoritative DNS servers, primary and secondary. Let’s see their differences.
Primary or master authoritative DNS server, the one that holds the zone file and the DNS records. The only server that allows modifications to DNS records. Due to this, the primary server has to inform and provide updates that contain all the changes made on its zone file. That’s why its functionality includes a “notify” feature. Through it, a primary server can notify a new update to the secondary server for this last to request it. To share an update with all the secondary servers, a zone transfer can be pushed.
Secondary or slave authoritative DNS server. This is a non-editable copy of the primary server. Redundancy is key, and always welcome not to risk important processes and information. This case is not an exception. Having a secondary server means having a useful backup and more. Through these copies, the traffic load can be distributed among servers to avoid stress. The more nameservers you can have for answering DNS requests, the quicker you can serve traffic. Secondary servers become points of presence (PoPs) where recursive servers can find the information users around the world request.
Authoritative DNS servers are important for different DNS processes to be executed. The domain name system (DNS) and, therefore, the Internet could not fully operate without them!