Jan 24
course nut's'n'bolts
- Copyright (see resources page)
- Welcome to My Classroom
- class website
- assignments
- turning in work - show example
- grade: weekly homework, class participation, midterm & final project
Wireshark 101
Same program as Ethereal in Matthew's textbook; just a new name and more recent version.
- discuss installation
- do demonstration live capture in class
- load simpleHttp.cap from textbook files
- ... and work through what's there
Some of the info in the textook is dated; don't take it all as gospel.
In particular, the "host name" filter syntax won't work. Instead
use "ip.host contains name", in the "Filter" part of Wireshark. For example,
ip.host contains gnu.org
We'll learn more about and explore this stuff as we go.
As you play around, the first rule is ...
If it doesn't work, ask. There is time to figure it all out.
Questions and background information : start with google ... then email Jim at mahoney@marlboro.edu
internet fundamentals
See
Open discussion of the fundamentals, including the following buzzwords :
- program, process, daemon, foreground, background, GUI, command line, OS
- internet, local network, wide network, 802.11, ethernet, network, bandwidth
- host, router, client, server
- protocol, port, IP, TCP, HTTP, SSH, DNS,
- browser, language, HTML, CSS, Javascript, client-side, server-side, request
- file types : .html .txt .php .css .js .jpeg .png .gif ...
- naming / addressing things : MAC, IP, DNS
networks & bits : basics
- wires, pipes, and packets : packets win
- historical : "1 conversation per wire" ... inefficient
- now : packets - more efficient, possible with computers
- everything is bits
- 1 bit = 0 or 1
- 8 bits = 1 byte = 1 ascii character
- binary, hex, and internet addresses
- in IP notation that's 69.164.211.150
- which is 4 clumps of 8 bits = 32 bits ; 0 to 2**32-1 = 4,294,967,295
my laptop's wireless MAC address (base 10) : 158501019633494
- in hex notation (from "About My Mac >> Network >> Locations") 90:27:e4:f8:c7:56
- which is 6 clumps of 8 bits = 48 bits ; 0 to 2**48-1 = 281,474,976,710,655
These two (IP=internet, MAC=ethernet) are the important address numbers.
- IP (internet addresses, wide area) are location/network based; assigned dynamically
- MAC (ethernet card addresses, local area) are built into the hardware; can't be changed
protocols
- what is a protocol?
- what are some internet protocols?
- what is "layering" of protocols?
coming up next
- Matt Dailey's packet capture example
- textbook Matthew's pg 27 & 28, questions on her simpleHttp.cap packet capture file.
