How the Internet Works
http:// means something after all
Objectives
Identify the components of a URL
View requests and responses in the browser
Make requests using something other than a browser
Identify the components of a request and response in HyperText Transfer Protocol
The Internet:
How does it work?
But like, for reals how does it work
Home of The Internet:
ARPANET
First implementation of TCP
First implementation of DNS
First computer system secure enough to share classified documents across a network
A Series of Tubes Layers
IP
TCP / UDP
Data Link (OS-level stuff)
HTTP
The Browser
Browser Server
IP
TCP / UDP
Data Link (OS-level stuff)
HTTP
The Browser
Literally cables and wifi
IP
TCP / UDP
Data Link
HTTP
The Server
IP
TCP / UDP
Data Link (OS-level stuff)
HTTP
The Browser
Peeling the layers of the onion
- Browser sends an HTTP Request
TCP / UDP
When someone says "Packets", think TCP / UDP layer
HTTP: The Layer you Deal With
Requests
Responses
To make an HTTP Request:
Identify a resource via it's uniform resource identifier
Input the identifier into a client
Direct the client to make a request
URIs
Uniform Resource Identifiers
cURL
Browsers aren't the only thing that can make requests
Postman
URIs
Uniform Resource Identifiers
URLs are URIs
URIs
Uniform Resource Identifiers
URLs are URIs
http://galvanize.com/blog/
IP
TCP / UDP
Data Link (OS-level stuff)
HTTP
The Browser
Peeling the layers of the onion
- Browser sends an HTTP Request
- The HTTP Request gets divided into packets
IP
TCP / UDP
Data Link (OS-level stuff)
HTTP
The Browser
Peeling the layers of the onion
- Browser sends an HTTP Request
- The HTTP Request gets divided into packets
- The packets are routed to their destination
IP
TCP / UDP
Data Link (OS-level stuff)
HTTP
The Browser
Peeling the layers of the onion
- Browser sends an HTTP Request
- The HTTP Request gets divided into packets
- The packets are routed to their destination
- The packets try to find a good route to their destination, travel across the wire as 1s and 0s
Tries to find a good route?
$ traceroute galvanize.com
Tries to find a good route?
Packets Contain a "TTL" header
Tries to find a good route?
Packets Contain a "TTL" header
TTL : Time to Live
Tries to find a good route?
Packets Contain a "TTL" header
TTL : Time to Live
Really means "don't visit more than x places when you're looking for a way to your destination"
HyperText Transfer Protocol
By LizTheDeveloper
HyperText Transfer Protocol
- 1,520