Intro to Networking

Aaron Kelly && Max Friedrich

Intro to Networking

Networking Models

Why are there two and What is difference?

OSI Model

Layer OSI
8 User
7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data Link
1 Physical

TCP/IP Model

Layer TCP/IP 4 TCP/IP 5 Protocols
4 Application Application HTTPS
3 Transport Transport TCP
2 Network Network IPv4
1 Network Access Data Link Ethernet
0 Physical Copper Twisted Pair

The Average Home Network

Image of a BTHub

What that Actually does?

Image of a Router, Switch and AP

MAC - Layer 2 addressing

This is a Ethernet thing that allows devices communicating over Ethernet to specify who they are talking to. That way, you can figure out if a frame is meant for you.

MAC is 6 bytes long. The first 3 are unique to the manufacturer and the last 3 are unique to the device.

E.g. 00:00:0A:BB:28:FC

IPv4 - Layer 3 addressing

IPv4 is used to address computers on a network. You can think of it like a physical address.

IP addresses are a set of 4 bytes, we generally write them in the form AAA.BBB.CCC.DDD. E.g.

How does IPv4 work?

Device IP
Router (In)
Router (Out)

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