Simon Griffee

How The Internet Works

4 September 2013 · 1 minute read

Jessica McKellar’s excellent How The Internet Works presentation:

Notes

You type http://python.org into your browser bar and press Enter. What happens?

Questions

  1. WHAT is python.org?
  2. WHERE is python.org?
  3. HOW does my computer talk to python.org?
  4. WHAT does my computer SAY to python.org?

Protocol

A format and rules for exchanging information. Internet protocols are layered, one protocol per task. Application-layer protocols that use TCP:

Answers

  1. WHAT: DNS for translating hostnames to IP addresses
  2. WHERE: IP for addressing and routing
  3. HOW: TCP for reliable delivery
  4. WHAT do we SAY: HTTP for requesting resources

Address Resolution Protocol (ARP) maps hardware (MAC) addresses to IP addresses. Local network traffic goes through gateway router (usually has IP address 192.168.1.1) and then out to internet.

See also:

What

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