As a rule, a DNS server refers to both the program used to form responses to DNS queries and the host itself used to run the DNS program. In this case, requests are managed using the appropriate protocol.
It is necessary
A computer with an internet connection
Instructions
Step 1
First of all, please note that depending on the function performed, DNS servers can be divided into several groups. Each of the server groups has its own specifics of action, and also contains subgroups of servers that have an even narrower purpose. Server hierarchy is usually associated with the presence or absence of any action rights in the coverage area.
Step 2
Note that the largest group of all groups is the authoritative DNS server group. The peculiarity of this group of servers is that they serve any zone. Each authoritative DNS server group has at least one primary server. Such an element of the group is capable of making changes to these zones, therefore it is also called the master server. In addition to the primary server, a zone can contain an unlimited number of secondary servers that do not have sufficient rights to make changes to any of the zone's data. Their work is based on receiving messages about any changes from the master server.
Step 3
If you are interested in the process of interaction between the server and the client, then delve into the work of a caching DNS server. The principle of operation of this system is associated with servicing requests coming from clients and interacting with higher-level DNS servers. A caching DNS server receives recursive requests from clients, then executes these requests through non-recursive requests to authoritative servers, and then passes the request to an upstream server.
Step 4
Note that in the case of serving clients that run on the same local machine, the local DNS server is used. Such a server repeats the principle of operation of a caching server, but is configured for use on the local machine. A redirecting DNS server does something similar. Such an application is capable of redirecting recursive requests it receives to an upstream caching server.
Step 5
Consider also how a registering DNS server works. It accepts dynamic updates from clients. Today, such a server is usually combined with a DHCP server. It can also work in the mode of a registering DNS server, receiving information from users of a given domain about the correspondence of, say, the name and IP address of a computer, thus updating the data of the domain zone.
