Domain Name System (DNS) is a protocol that is used for resolving names to the IP addresses. It is used over the Internet when you browse a website, and then the DNS resolves the web server name to an IP address. It is also used in enterprise networks when looking for a server name that is translated to an IP address.

Hyper Text Transfer Protocol (HTTP) and Secured HTTP (HTTPS) are both used for browsing the Internet, or connecting to other software that are hosted inside your organization or in the cloud. HTTPS is used when we secure HTTP with SSL/TLS in order to hide the clear text data exchange from hacking. It is used when connecting to your bank, webmail account (for example, Gmail or Hotmail), or any other secured application.

In this chapter, we will discuss these protocols, how they work, and how to use Wireshark in order to find common errors and problems in them.