📚 Knowledge Library — Topic 3.10A — Hardware

NIC, MAC and IP Addresses

Understand how devices are identified on a network, and why a MAC address and an IP address are not the same thing.

Start LearningWorked Example
1. Invitation

Every device on a network needs an identity.

When a computer joins a network, other devices need a way to recognise it.

Two important addresses help with this: a MAC address and an IP address.

💡 Remember: both identify devices, but they do different jobs.
Figure 1.1
Device Identity
Laptop
↓
MAC address
+
IP address
2. Big Idea

The NIC lets the device join the network.

A NIC stands for Network Interface Card.

It is the hardware that allows a device to connect to a network, send data and receive data.

💡 NIC = the network connection hardware inside or attached to the device.
Figure 2.1
Network Interface Card
Computer
↓
NIC
↓
Network
3. FutureLogic Bridge

MAC is like a national ID. IP is like a hotel room number.

A MAC address is permanent. It is assigned by the manufacturer.

An IP address is assigned when the device joins a network. It can change.

💡 Bridge: MAC = who the device is. IP = where it is on the network.
Figure 3.1
ID vs Location
MAC address
= permanent ID

IP address
= network location
4. Worked Example

What does a MAC address look like?

A MAC address is usually written in hexadecimal, separated into groups.

It is static and is assigned by the manufacturer of the NIC.

Example MAC address

3A:5F:12:9B:CD:80
Hexadecimal
6 groups
Static
Figure 4.1
MAC Format
XX:XX:XX
:XX:XX:XX
Six groups of hexadecimal digits.
5. IP Address

An IP address identifies a device on a network.

An IP address is used to identify where a device is on a network.

Unlike a MAC address, an IP address can be dynamic, which means it may change when the device reconnects.

IPv4 example

192.168.1.24
Figure 5.1
IPv4
4 groups
•
separated by dots
•
0 to 255
6. IPv6

IPv6 gives many more possible addresses.

IPv6 uses hexadecimal and is much longer than IPv4.

It uses 8 groups separated by colons, giving far more possible addresses.

🎯 Exam Tip: IPv4 uses dots and denary. IPv6 uses colons and hexadecimal.
Figure 6.1
IPv4 vs IPv6
IPv4
dots + denary

IPv6
colons + hex
7. Exam Tip

Do not mix up who assigns each address.

The MAC address is assigned by the manufacturer.

The IP address is assigned on the network, often by a router.

AddressAssigned by
MAC addressManufacturer
IP addressNetwork / router
🎯 Exam Tip: router assigns IP addresses, not MAC addresses.
Figure 7.1
Who Assigns It?
Manufacturer
→
MAC

Router
→
IP
8. Common Mistake

Characteristics are not the same as purpose.

If a question asks for characteristics of a MAC address, describe what it looks like or how it behaves.

Do not only write that it identifies a device.

⚠️ Common Mistake: for MAC characteristics, write hexadecimal, static, 48 bits, six groups — not just “identifies the device”.
Figure 8.1
MAC Characteristics
Hexadecimal
Static
6 groups
48 bits
Manufacturer ID
9. Summary

Network addresses in one screen.

A NIC allows a device to connect to a network.

A MAC address is a permanent hexadecimal address assigned by the manufacturer. An IP address identifies a device on a network and may change.

💡 Key idea: MAC = permanent device ID. IP = network address.
Figure 9.1
Final Check
NIC connects
↓
MAC identifies device
↓
IP identifies network location