WHAT WE LEARNED FROM ONIONS?

What happens when you type google.com into your browser and press enter?

An opinionated presentation about the OSI Model and the Internet for Fab Academy

Transcript

1. WHAT WE LEARN FROM ONIONS? Networks and the Internet
7. What happens when you type google.com into your browser and press enter?
14. What happens when you type google.com into your browser and press enter?
15. LAYER 1 Physical
20. $ traceroute
21. LAYER 2 Data Link
23. ARP and MAC How we address the physical? or how we glue Layer 2 and 3 together to built a network
24. FF:FF:FF:FF:FF:FF
 
 48-bits
 
 281.474.976.710.656 combinations
25. Sender MAC: interface:mac:address:here Sender IP: interface.ip.goes.here Target MAC: FF:FF:FF:FF:FF:FF (Broadcast) Target IP: target.ip.goes.here Sender MAC: target:mac:address:here Sender IP: target.ip.goes.here Target MAC: interface:mac:address:here Target IP: interface.ip.goes.here
26. LAYER 3 Network
28. IP Where I am and where I want to go?
29. 216.58.209.78
 
 32-bits
 
 4.294.967.295 combinations
30. 2a00:1450:4003:80a::200e
 
 128-bits
 
 340.282.366.920.938.463.463.374.607.431.768.211.455 combinations
31. $ ping
32. A NETWORK of NETWORKS LAN and INTERNET
33. DHCP The LAN wizard this is already layer 4!
34. $ wireshark
35. ROUTING 192.168.0.14 > 172.217.168.174
38. $ ifconfig
39. LAYER 4 Transport
40. TCP PORTS Once there, what I want?
41. 443 (https) 80 (http) 22 (ssh) 53 (dns)
42. NAT How we bridge local networks with the internet?
44. LAYER 7 What's the purpose of all this layers? Applications!
45. DNS The internet phonebook
47. $ host
48. $ whois
49. HTTP The Web
50. $ telnet google.com 80
 
 GET / HTTP/1.1 Host: www.google.com
51. $ curl
52. LAYER 6 An everyday example
53. TLS the "s" in https
55. symmetric cryptography
56. VPN the power of the "onion"
58. TOR the true onion
60. What happens when you send an Email? Or a MQTT message from your Arduino to Node-Red?