Protocols:

A protocol is a set of rules by which data is handled or transmitted. The protocol that should be used is determined by the situation and type of data that needs to be handled. For example, there are different protocols used for transferring files than for accessing the internet.

Ports:

Ports are points in a network that represent the endpoints of a connection. Different ports host different protocols, these are standardized. There are a total of 65,535 ports, with the common port numbers being around the first 1000. Here are some of the more important port numbers and protocols for security:

• 20 & 21: File Transfer Protocol (FTP), used for the transferring of large files
• 22: Secure Shell (SSH), used to establish secure connections
• 53: Domain Name System (DNS), used to resolves IP addresses to domain names to allow for easier navigation of the internet
• 80: Hypertext Transfer Protocol (HTTP), used to load webpages
• 443: Hypertext Transfer Protocol Secure (HTTPS), used to load webpages, but a more secure version. Websites that still use only HTTP can be unsafe.

There are a multitude of other ports that are used in security, but these were just some common ones. Packet capturing software, such as Wireshark, is used to capture communication between systems and format it in analyzable logs that show the order in which protocols were used. Sometimes, it is good for security professionals to be familiar with ports and protocols so they have no trouble understanding these logs and analyzing trends or suspicious activity in their system.