Lesson 4 of 5
Wi-Fi and Networks
Understand how radio waves, routers, switches, and MAC addresses connect your local devices to the wide world.
Learn it
Wi-Fi allows your phone or laptop to talk to your home router without any physical cables. It converts digital 1s and 0s into invisible radio waves travelling through the air.
Your home router acts like a traffic warden. It gives every gadget in your house a local address and makes sure information from the wider internet goes straight to the right screen.
Key terms
- LAN (Local Area Network)
- A computer network covering a small geographical area, like a home, school, or office.
- Router
- A network device that forwards data packets between different computer networks.
- MAC Address
- A unique hardware identifier permanently assigned to a Network Interface Card (NIC).
- NAT (Network Address Translation)
- A method that re-maps local private IP addresses to a single public IP address for internet access.
Analysing Network Bands
Compare the physical properties of the two main Wi-Fi frequency bands.
- 12.4 GHz Band Properties: Travels further through walls and solid obstacles, but offers lower top data transfer speeds.
- 25 GHz Band Properties: Delivers substantially faster data rates with less interference, but has a shorter physical range.
- 3Channel Allocation: Routers select specific sub-channels (like Channel 1, 6, or 11 on 2.4GHz) to avoid overlapping neighbour signals.
- 4Network Encryption: Modern routers use WPA3 encryption to secure wireless radio frames against eavesdropping.
Comparing Local vs Public IP Addresses
textLocal Home Network (LAN):
- Laptop: 192.168.1.10 (MAC: 3A:8B:4C:12:90:A1)
- Phone: 192.168.1.15 (MAC: 8C:3D:20:FE:44:0B)
- Console: 192.168.1.22 (MAC: B4:1E:5A:6D:77:F9)
Router WAN Interface (NAT Gateway):
- Public IP: 82.165.197.1
All LAN devices appear to the public internet under 82.165.197.1!NAT allows dozens of household devices to share a single public IP address while maintaining distinct private addresses on the local network.
Try it
Evaluate these statements about Wi-Fi and local networks:
A MAC address is permanently bound to a device network interface card.
5 GHz Wi-Fi signals travel through thick brick walls more easily than 2.4 GHz signals.
Network Address Translation (NAT) allows multiple local devices to share one public IP address.
Ethernet cables use radio frequencies to transfer internet data through the air.
Challenge
Check your own computer's local IP and MAC address using your system settings or command prompt.
Pick whichever way suits you — every mode earns the same bonus XP.
Write at least 40 more characters to submit.
Mark your own work
Guided walkthrough — 0/5 clues revealed
- Clue 1 locked — reveal it only if you get stuck.
- Clue 2 locked — reveal it only if you get stuck.
- Clue 3 locked — reveal it only if you get stuck.
- Clue 4 locked — reveal it only if you get stuck.
- Clue 5 locked — reveal it only if you get stuck.
Each clue costs 4 XP (never below 20 XP). You'd earn 40 XP right now.
Extension: Find the default gateway address listed; that is the internal private IP address of your home router.