Hardware & Networking Devices
The physical engines that power the internet.
MODEM
(Modulator-Demodulator)
Transforms data between digital (computer) and analog (telephone/cable) formats.
NIC CARD
(Network Interface Card)
The physical connection hardware in your PC. Every NIC has a unique MAC Address.
The Splitter
A Splitter is a passive device that splits one physical connection into multiple paths.
Critial Fact: Only ONE device can be active at a time!
HUB (Layer 1)
Dumb Device: Broadcasts data to EVERY port. High collision risk.
BRIDGE (Layer 2)
Segmenter: Connects two LAN segments. Filters traffic based on MAC.
SWITCH (Layer 2)
Smart Device: Forwards data ONLY to the destination port (MAC Table).
The Router (The Brain)
- Layer 3 Device: Operates using IP Addresses.
- Function: Determines the best path between different networks.
- Routing Table: Maintains a map of the internet to forward packets.
| Device | OSI Layer | Intelligence | Addressing | Logic |
|---|---|---|---|---|
| HUB | Layer 1 (Physical) | Dumb (Blind) | None | Broadcasts to ALL ports. |
| BRIDGE | Layer 2 (Data Link) | Passive/Learning | MAC Address | Connects 2 LAN segments. |
| SWITCH | Layer 2 (Data Link) | Smart (Learning) | MAC Address | Unicast (Point-to-Point) forwarding. |
| ROUTER | Layer 3 (Network) | Intelligent | IP Address | Finds best path across networks. |
Summary Flow
Hub: Zero filter → Bridge/Switch: MAC filter → Router: IP filter.
- الـ Hub: مبيفهمش حاجة، بيبعت كل حاجة لكل الناس.
- الـ Bridge والـ Switch: بيفهموا الـ MAC Address، السويتش أسرع وأذكى في التعامل مع أجهزة كتير.
- الـ Router: ده الزعيم، بيفهم الـ IP Address وبيربط شبكات ببعضها مش مجرد أجهزة.