Notes on networking

These are mainly notes on the course Grokking Computer Networking for Software Engineers. It taught me a lot about computer networking, and the notes I took mean I don't have to pay for it again.

Fundamentals

TCP IP – the Internet protocol suite: the end-to-end argument, packet switching, and the layered model.
Network Topology – bus, ring, and star layouts.
Extras – types of networks by geography (LAN, MAN, WAN, SONETSDH).

Application Layer – responsibilities, and client-server vs peer-to-peer architectures.
How processes communicate – programs vs processes vs threads, sockets, ports, and addressing.
HTTP – objects, URLs, persistent vs non-persistent connections.
- HTTP Requests – the request line, HTTP methods, URIs, and header lines.
- HTTP Responses – the status line, status codes, and header lines.
DNS – the domain name lookup service, namespace hierarchy, and local caching.

Transport Layer – segmentation, multiplexing, and congestion control.
Reliable Data Transfer – checksums, retransmission timers, and pipelining.
TCP – reliable, connection-oriented transport and the three-way handshake.
TCP Segment Header – header fields and flags in detail.
UDP – connectionless transport: the datagram header and when to prefer it over TCP.