DNS is essential for the Internet. Identifying and eliminating the causes of errors requires a comprehensive understanding of the relationships.
Reading time:
25 minutes
In your pocket save
(Image: KI Midjourney | Collage c’t)
What is a domain name system server and why do you need one? Probably all IT experts immediately have an answer to this seemingly simple question: a device sends a DNS request, i.e. a domain name with a resolution request, to the DNS server and receives a response in the form of an IP address.
That’s not wrong, but if you look closely, DNS is a swarm of different DNS servers with clearly defined roles. Likewise, there are many types of DNS requests and responses. We have summarized the essential elements, functions and data flows in one large infographic so that you can see connections and contradictions. Based on this, we explain the most important DNS questions and answers.
First the main features: DNS is a globally distributed database based on the Internet Protocol (IP). From a hierarchical point of view, the different servers are organized in a decentralized way in a tree structure. The main task is to maintain relationships between domain names (domains for short) and IP addresses and to release IP addresses upon request from Inter and Intranet hosts (clients). Even if hosts such as PCs, smartphones, smart TVs or routers communicate with servers and cloud services exclusively via IP addresses, they would be overloaded with memories of the IP addresses of all the servers in the world and would only need a fraction of them.
