Study
In the late 90's I realized the best way for me to learn something was to research how it works, write a tutorial for myself that covers the main concepts, and then post it online for me to reference when needed. This portion of the site is an archive of that content.
Popular
A tcpdump Primer
A primer and reference on tcpdump.
A Security-focused HTTP Primer
An overview of HTTP basics from the perspective of information security.
An lsof Primer
A guide to using some of lsof's functionality.
Information Security
A Security-focused HTTP Primer
A collection of information about the HTTP protocol, from the security perspective.
Cross-site Scripting (XSS) Explained
A simple explanation of the basics of XSS.
Cross Site Scripting (XSS) Explained [Short Version]
An explanation of the basics of XSS in 13 list items.
An Introduction to Zone Transfers
An introduction to Zone Transfers, including how to perform them using host, dig, and nslookup.
The Difference Between a Vulnerability Assessment and a Penetration Test
It seems there is never-ending debate on this topic and I believe this essay finally removes the controversy.
What To Tell People When They Ask How To "Hide" Their IP Address On The Internet
How to explain the basics of Internet anonymity to beginners using an analogy.
Security and Obscurity: Bad Alone, Good as a Layer
A short essay on how most people get obscurity wrong.
The Difference Between Encoding and Encryption
A concise clarification between these two ways of manipulating data.
The Birthday Attack
An explanation of the birthday paradox.
The Diffie-Hellman Protocol
My basic overview of this remarkable protocol.
A Security-focused HTTP Primer
A look at the HTTP protocol from the perspective of information security.
Daniel's Information Security Concepts Primer
My overview of the key information security concepts.
Not all SYN packets are created equal
A look at how SYN packets created via raw sockets differ from those created with a call to the connect() syscall, and how this effects portscanning.
A Firewall Primer
A short firewall primer aimed at explaining the differences between different types of firewall technologies.
An iptables (netfilter) Primer
A short walkthrough of Linux firewalling basics.
An nmap Primer
A quick guide to some essential functionality within nmap.
Development
A git Primer
An overview of git's fundamentals.
Networking
How Network Ports Work
How to explain the concept of network ports to beginners.
The Hyperlink Trailing Slash
Why you should use a trailing slash on your directory hyperlinks. Includes proof.
Windows File Sharing
A brief overview of the various Windows file sharing technologies.
A tcpdump Primer
A primer and reference on tcpdump.
Subnetting
An alternative approach to subnetting..
How to Remember Your TCP Flags
An acronym for remembering your TCP flags..
ICMP Basics
Most of what most need to know about ICMP..
Unix/Linux
A Varnish Primer
Has nothing to do with painting. This gives the basics of Varnish and how to administer it..
A Unix/Linux Permissions Refresher
A short refresher on Unix/Linux permissions..
Carriage Returns and Line Feeds
Taking the guesswork out of *nix and Windows text file handling.
How to Set Your IP in Linux
A quick reference for setting your IP manually in Linux.
The find Command
A summary of some of the most useful options for find, including how to use it with xargs.
An lsof Primer
A guide to using some of lsof's functionality.
A Basic Guide to vim
Some basics for functional (and more) with vim.
Hexedit
A short guide to using hexedit to edit the text within binary files such as sshd.
Using the tr Command
A short guide on using tr to translate text.
The tar Command
Most everything you need to know about the tar command.
Miscellaneous
Encoding and Character Mapping
A fairly involved guide to understanding how characters are mapped and encoded. Covers ASCII, Unicode, etc.
URLs vs. URIs
A short discussion of the debate between referring to web addresses as URLs vs. URIs.
Wardrobe
A resource for learning and remembering the proper way to dress (men).
Class
A resource for understanding class in America. Extremely raw at this point.
Positional Number Systems
Never again forget your binary or hex math.
Horsepower vs. Torque
A discussion of which attribute of an engine is more tied to acceleration.
Glossary
A deprecated page I abandoned long ago.
One of the first guides to using Google. Now highly irrelevant.
Coffee
Confused about the differences between all the different kinds of coffee, the roast levels, and the various drinks? I was too, but not anymore.
Photography
Some photography basics for those getting started who want to understand fundamentals.
My Ümlaut Page
I have a whole page just for the ümlaut. It's probably not what you're thinking.
Politics
Some basic definitions for terms thrown around carelessly in political debates -- usually without much actual knowledge.
The Table Tennis Loop
My secret to generating speed and speed for the table tennis loop.