Networking Overview

TODO:

this page is abysmal. fix.

Resources

router overview

https://www.uhcl.edu/computing/information-security/tips-best-practices/routers

Tutorials

code a TCP/IP stack

https://www.saminiir.com/lets-code-tcp-ip-stack-1-ethernet-arp/

5-layer TCP/IP model

-	layer	protocol	unit	address
1	physical	10 Base T, 802.11	Bits	n/a
2	datalink	Ethernet, WiFi	Frames	MAC addr
3	network	IP	Datagram	IP addr
4	transport	TCP, UDP	Segment	Ports
5	application	HTTP, SMTP, ..	Messages	n/a

Example Transaction

TODO:

this takes a lot of space, and is not very helpful. Find a better way to describe this.

An example might help this sink in.

visit a website: #(GET request on server's port 80)

transport (HTTP)
   request is sliced into segments(transport) of 536 bytes or smaller

network (TCP/IP)
   if network knows how to reach destination, each segment is wrapped in
   TCP/IP info, and handed off to the datalink layer.

datalink (MAC,ARP)
   Adds information about the physical protocol (ethernet, token-ring, ...) 
   and fires the data to a target MAC address.

---

physical
   the information is sent over the wire

--- 

On the receiving end, datalink, and network layers are stripped off, and all 
segments (transport) are re-assembled to form the request. This is handed to
the web-server, which then repeats the above with a reply.

Layers

Physical

coax

optical

Transport

Protocols
tcp