The Domain Name System (DNS) is a database that stores IP addresses and domain names. It bridges the gap between human and computer languages to keep people and servers happy. DNS is like a sophisticated address book for the internet. But unlike an address book, DNS does not reside on one physical location, but instead consists of multiple servers that communicate regularly with each other to create the directory information. This redundancy and efficiency are critical to the success of DNS.
It works by mapping the domain name to an IP address. This mapping process is controlled by the designated authoritative name servers. DNS is the foundation for the Internet. This system has become an essential part of our daily lives. DNS allows us to search for and retrieve information from any web site we want, no matter how remote. It is essential to understand DNS and its various functions. DNS makes the Internet work more efficiently. But before we get into the details of DNS, let’s first discuss the basic concept.
In the DNS protocol, name servers can be either primary or secondary. There was a time when these terms were used interchangeably, but this is no longer the case. The primary server stores the original copies of zone records, while the secondary server maintains a copy of those records. The authoritative name servers of a zone must include a Start of Authority (SOA) record. The minimum field of the SOA record is used to determine the TTL value for the negative answer.
While DNS can be useful for connecting to websites and other services, it does have some security risks. DNS records can be misused and manipulated by attackers. Internal DNS servers are untrustworthy, as the information stored in them is not authoritative. In addition, DNS caches are not authoritative. Therefore, attackers have learned how to use DNS to set up covert channels to exfiltrate data. It is important to ensure that your DNS server is safe and secure.
While DNS information is shared between many servers, it is also cached locally on individual computers. This prevents computers from querying name servers for commonly-used IP addresses. DNS servers also have a “root nameserver” which translates human-readable host names into IP addresses. The root nameserver is the authoritative DNS server for the domain. It is the authoritative DNS server, or “A” in the Internet world. It is the definitive source of domain DNS information.