Many Missing Topics

[eatnumber1]

I posted this to facebook, and my friends commented on quite a few things missing. I figure that I should bring it up here as a TODO for things that need to be written.

A brief summary of the things said on facebook include:

• nsswitch
• DNS hierarchy
• CAs & certificate pinning
• The Internet
  • Routing protocols (BGP, OSPF, IS-IS, etc.).
  • AS numbers
  • Proxies
  • Content caching devices
  • Firewalls
• Cookies

[sawall]

Along similar lines:

• Most of "opening a socket" needs a rewrite from a network perspective. When it talks about the socket being established it sounds like OSI is an API rather than an abstract model.
• How TCP actually works isn't described (window sizing is notably absent).
• Load balancers should also be mentioned along with firewalls and proxies as you've already suggested.
• NAT should be mentioned since most home users are behind it. DHCP and IP addressing would also need some discussion.
• Some mention of the likelihood of trunking/MPLS/QoS within Tier 1 would probably be appropriate to go along with the packet forwarding discussion.
• Discussion of how packets are forwarded within the user's ISP as well as within Tier 3 would be useful.

I notice that #16 has some similar comments.

[daodennis-zz]

I recommend we split each one of these into separate bugs, mostly because some of these topics already have multiple bugs filed against them with varying levels of quality. We can't possibly address all of these issues in one bug. I did this with the DNS one and came up with a few things and hope to eventually just submit a PR after letting it bake a little bit.