A+, Network+, Security+ Exams in a Nutshell

Protocols and Standards

This section covers a study of different networking protocols and standards. First, I will explain the OSI networking model and then discuss commonly used networking protocols. I will explain how networking protocols are associated with network operating systems. This will be followed by a detailed study of the TCP/IP protocol suite, which are the most widely used networking protocols on private networks. The TCP/IP protocol suite is the only one used on the Internet.

Media Access Control (MAC) Address

The MAC address is a unique 48-bit (6 bytes) hardware address that is hardcoded into almost every networking device. This address is used by network protocols to deliver data to the correct host in the network. In devices that have multiple network interfaces, each interface has a unique MAC address. The Data Link layer of the OSI model is responsible for managing MAC addresses of network devices in the network.

The 48-bit MAC address is written as hexadecimal numbers in six groups of two bytes each, separated by colon (:) signs or hyphens (-). These numbers include 0 to 9 and A to F. The first group of 3 bytes (24 bits) uniquely identifies the manufacturer of the device and is assigned by the IEEE. The last group of three bytes is assigned to the interface by the manufacturer to uniquely identify the interface. This ensures that no two devices have an identical MAC address. The following is an example of a MAC address:

02-25-4F-89-AE-48

Network protocols, such ...