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# ItC Week 13 - Network

###### tags: `Intro_to_Comp`

- ## Network Interface Card
- Every networked device must have one
- some motherboards/laptops might have both a wired one and a wireless one
- Each NIC has an IP address (logical address) and a physical address (MAC address)
- MAC address is unique, given to a NIC at factory
- MAC addresses are used within LAN
- IP addresses are used accross different nerworks

- ## Hub
- Connects network devices
- A device sends a message to the hub, and the hub send that message to all the other connected devices
- unintended recipients should ignore bogus traffic
- Can only deal with one message at a time

- ## Switch
- Acts like a hub, but only direct the traffic to intended destination instead of spamming all devices
- An "Intelligent hub"
- Avoid "packing sniffing" when message is not encrypted

- ## Routers
- Different networks connect via routers (NOT switch or hub)
- Can connect networks with different protocols
- Gateway router
- your computer &rarr; gateway router &rarr; a computer on the other network
- your computer &rarr; gateway router &rarr; ISP's network (Internet)

- ## TCP/IP & Packet
- Provides the technical foundation for public internet
- Layers
- Applications
- Transport
- Internet
- Network Interface
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- ## Wireless Networking
- WiFi : a means of implementing WLAN
- aka 802.11

- ## Some Scenario
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