DNS

I believe having a solid understanding of the hierarchical naming system for anything connected to the Internet will make your security tasks easier. DNS stands for Domain Name System. Since 1985, DNS has been an essential component of the Internet. It provides a global, distributed directory service. It coordinates information with domain names assigned to a numerical IP address. It is much harder for us as humans to remember the four octets for every website we want to visit. It is much easier to remember www.example.com.

There are 4,294,967,296 IPv4 addresses. It would be very difficult to build and maintain a database of all those IPv4 addresses in just one place. With the addition of the 340,282,366,920,938,463,463,374,607,431,768,211,456 IPv6 addresses, it is mind‐boggling. It is estimated there are 7.7 billion people on Earth. That is more than a trillion IP addresses assigned to every single person on this planet. We need a way to track all these addresses. Actually...