3.9 Network Hardware Trainer
NIC, router, MAC address, IP address, transmission media — everything needed to connect devices on a network.
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What do I need to know before I start?
A network connects two or more devices so they can share data and resources. Every device needs a NIC (Network Interface Card) to connect, and each NIC has a unique MAC address set by the manufacturer. Data travels in packets, and a router reads each packet's destination address to forward it. Devices are identified by IP addresses — either IPv4 (32-bit, denary, dots) or IPv6 (128-bit, hexadecimal, colons) — which can be static or dynamic. Cambridge tests all of this with precise definitions and comparisons.
By the end of 3.9 you can…
| Objective | Why it matters |
|---|---|
| Describe the purposes of a NIC | s25 Q5a: transmit/receive data, provide a physical connection, convert data for transmission. |
| Identify three characteristics of a MAC address | s25 Q5a(ii) — 3 marks; s22 Q10 — 3 marks. Unique, set by manufacturer, identifies the device. |
| State the role of a router | Reads each packet's destination address and forwards it towards the correct network/device. |
| Compare IPv4 and IPv6 | s23 Q9b — 4 marks: bit-length, notation and number of addresses all differ. |
| Distinguish static and dynamic IP addresses | Static never changes; dynamic is assigned on connection and can change. |
| Explain the difference between a MAC address and an IP address | MAC identifies the device (fixed); IP identifies its location on the network (can change). |
Cambridge-approved terms
Network Interface Card — hardware that connects a device to a network and transmits/receives data.
A unique address set by the manufacturer that identifies a device (NIC). Does not change.
An address identifying a device's location on a network. Can be IPv4 or IPv6; can be static or dynamic.
A device that reads each packet's destination address and forwards it towards the correct network.
IPv4: 32-bit, denary, separated by dots. IPv6: 128-bit, hexadecimal, separated by colons.
Static: never changes. Dynamic: assigned when the device connects and may change each time.
The key comparisons
MAC address vs IP address
| MAC address | IP address | |
|---|---|---|
| Identifies | The device (NIC) itself | The device's location on the network |
| Set by | The manufacturer | The network / ISP |
| Changes? | No — fixed and unique | Can change (dynamic) or stay fixed (static) |
IPv4 vs IPv6
| Feature | IPv4 | IPv6 |
|---|---|---|
| Bit-length | 32-bit | 128-bit |
| Notation | Denary, separated by dots (e.g. 192.168.0.1) | Hexadecimal, separated by colons |
| Addresses | Far fewer — running out | Vastly more — solves the shortage |
Traps that regularly cost marks
A MAC identifies the device and is fixed; an IP identifies its network location and can change.
The MAC address is set by the manufacturer, not the network or ISP.
IPv4 is denary with dots (32-bit). IPv6 is hexadecimal with colons (128-bit).
No — MACs come from the manufacturer. Routers forward packets using destination addresses.
Static never changes; dynamic is assigned on connection and may change. Don't swap them.
Give specific purposes: transmit/receive data, physical connection, convert data — not just "connects to the network".
Check yourself — tap to reveal
Answer in your head, then tap to see the model answer. Aim for 5 of 6 before moving to Learn.
✅ Ready for Learn?
Before moving on, make sure you can answer these without notes:
- What is a NIC and what are its purposes?
- Give three characteristics of a MAC address.
- What does a router do with a packet?
- Compare IPv4 and IPv6.
- How does a MAC address differ from an IP address?
Network hardware
NIC
Network Interface Card. Connects a device to a network. Each NIC has a unique MAC address. Can be wired or wireless (WNIC).
Router
Examines the destination address in a data packet and forwards the packet to that address. Connects devices to the internet.
Transmission media
The cables (e.g. copper, fibre optic) or wireless signals (radio waves) that carry data in a network.
Network flow animation
Press Send to see how a packet travels through the network.
MAC address vs IP address
| MAC address | IP address | |
|---|---|---|
| Set by | Manufacturer (burned in) | Network / router / DHCP |
| Changes? | No — permanent | Yes (dynamic) or No (static) |
| Format | Hexadecimal (34:4D:EA:89:75:B2) | IPv4: 12.244.233.165 / IPv6: 2001:0db8:… |
| Unique to | The NIC / hardware | The network connection |
| Used for | Identifying device on local network | Routing packets across internet |
IPv4 vs IPv6
IPv4
32-bit address. Four groups of numbers separated by full stops. E.g. 12.244.233.165. Created 1983. Running out of addresses.
IPv6
128-bit address. Eight groups separated by colons. Can include hex. E.g. 2001:0db8:0000:…:7879. Created because IPv4 running out.
Static vs Dynamic IP
Static: does NOT change each time the device connects. Used for servers, printers.
Dynamic: CAN change each time the device connects. Assigned by DHCP. Most devices use dynamic.
Activity 1 — MAC or IP?
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Activity 2 — Name that Component
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Activity 3 — Spot the Mistake
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Practice questions
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Cambridge-style questions
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Review quiz
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Exam traps
Memory triggers
🧠 "MAC = Made At Creation"
MAC address is made when the NIC is created (manufactured). Permanent. Never changes.
🧠 "Router = Royal Mail sorter"
A router reads the address on each packet and sends it to the right destination. Like a postal sorting office.
🧠 "IPv6 = more digits, more devices"
128-bit vs 32-bit. More bits = more possible addresses = enough for all devices worldwide.