MAC addressing in Computer Networks - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does MAC stand for in MAC addressing?

MAC stands for Media Access Control. It is a unique identifier assigned to network interfaces for communications on the physical network segment.

beginner

How many bytes long is a MAC address?

A MAC address is 6 bytes (48 bits) long. It is usually shown as 12 hexadecimal digits.

beginner

What is the typical format of a MAC address?

A MAC address is typically written as six groups of two hexadecimal digits, separated by colons (:) or hyphens (-), for example: 00:1A:2B:3C:4D:5E.

intermediate

Who assigns the first half of a MAC address and what does it represent?

The first half (first 3 bytes) of a MAC address is assigned by the IEEE to manufacturers and is called the Organizationally Unique Identifier (OUI). It identifies the device maker.

intermediate

Can MAC addresses be changed by users?

MAC addresses are usually fixed by the manufacturer, but some devices and software allow users to change or 'spoof' the MAC address temporarily.

What is the length of a MAC address?

A 48 bits

B 32 bits

C 64 bits

D 128 bits

A MAC address is 48 bits long, which equals 6 bytes.

Which part of the MAC address identifies the manufacturer?

A First 3 bytes

B Last 3 bytes

C Middle 2 bytes

D Entire 6 bytes

The first 3 bytes of a MAC address are the Organizationally Unique Identifier (OUI) assigned to manufacturers.

Which of the following is a valid MAC address format?

A 192.168.1.1

B 255.255.255.0

C 00:1A:2B:3C:4D:5E

D http://example.com

MAC addresses are shown as six groups of two hexadecimal digits separated by colons or hyphens.

Can MAC addresses be changed by users?

A Yes, always

B Sometimes, with special software

C No, they are permanently fixed

D Only by the manufacturer

Users can sometimes change or spoof MAC addresses using special software or device settings.

What does MAC addressing help with in a network?

A Routing internet traffic

B Assigning IP addresses

C Encrypting data

D Identifying devices on the local network

MAC addresses uniquely identify devices on the local network segment for communication.

Explain what a MAC address is and why it is important in networking.

Think about how devices recognize each other on the same network.

Describe the structure of a MAC address and the role of the Organizationally Unique Identifier (OUI).

Consider how the address shows who made the device and which device it is.