Wireless access points, Routers, Switches, NIC (Network Interface Controller/Card), Transmission media

The hardware needed to connect stand-alone computers into a Local Area Network: Wireless access points, Routers, Switches, NIC (Network Interface Controller/Card), Transmission media

1.3.1 Networks and topologies

Practise exam questions

Networks and topologies — Note 4 of 10

What you need to know

Several hardware components are needed to connect standalone computers into a Local Area Network, including wireless access points, routers, switches, NICs, and transmission media. A home 'router' is often three devices in one box: a router (between your LAN and the Internet), a switch (Ethernet ports on the LAN), and a wireless access point.

What to know

Router
- Receives packets from connected networks.
- Forwards, sends, or transmits packets towards the destination (usually via the next hop on the path).
- Maintains a routing table: stored information that describes available paths, interfaces, and next hops so the router knows where to send traffic for a given destination.
- Identifies the most efficient (or valid) path towards the destination using the destination IP / logical location on the network.
- A home 'router' usually contains a built-in switch (and often Wi-Fi) — that SWITCH forwards to the correct MAC on your LAN.
Switch
- Operates on a LAN (local network) to connect devices within that single network.
- Uses MAC addresses (not IP addresses) to decide which port/device should receive the data.
- Sends data only to the intended device once it has learned MAC-to-port mappings (not to every device).
A switch builds a MAC address table (which MAC address is on which port) and uses it to forward frames only to the correct port.

Key terms

Wireless Access PointWAP: Uses radio transceivers to allow devices to connect wirelessly to a network.
Router: Connects two or more DIFFERENT networks together (e.g. a home LAN to the Internet). Uses IP addresses to make routing decisions between those networks.
Switch: Connects devices within ONE network (typically a LAN). Uses MAC addresses (not IP addresses) to send data only to the intended device.
NICNetwork Interface Controller/Card: Hardware inside a device that enables it to connect to a network. Converts data into signals (voltages for wired, radio waves for wireless).
Transmission Media: The physical or wireless methods used to carry data (e.g. Ethernet cables, fibre-optic cables, radio waves).

Exam technique

Tip:Router = between networks, decisions based on IP (logical addressing). Switch = inside one network, delivery based on MAC (hardware addressing on the LAN).
Mistake:Saying the router sends data to the correct MAC address on the local network as its main job. Routing between networks uses IP; delivering to a specific device's MAC on the LAN is what a switch does. A home 'router' usually contains a built-in switch (and often Wi-Fi) — that switch part forwards to the correct MAC on your LAN.
Mistake:Confusing a router with a switch. A router connects NETWORKS (e.g. your home LAN to the Internet). A switch connects DEVICES within a single network.
Mistake:Saying a switch performs the same role as a server. A switch DIRECTS data to devices — it does NOT store data or provide services.

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