About this page

Every two weeks, the Western Cape Linux Users Group give a talk/lecture, usually about Linux.

Every now and again I happen to give one of these lectures and this page is dedicated to those lectures. You can find all the notes, diagrams, documents, code, etc. that I use when preparing for these lectures on this page.

November 2005 - SQLite

This talk covered SQLite, a lightweight SQL database engine. Unfortunately there's no notes for this talk, but you can find more information about this software below:

March 2005 - Advanced Routing in Linux

This talk covered advanced routing in Linux: iproute2, source routing, etc. You can download my slides below:

September 2004 - Linux Startup

Marc and I gave a talk about Linux startup. He covered init and I showed everyone how to create boot disks, how pivot_root, chroot, linuxrc, etc. works. No notes this times, but if enough people ask me for it I can add all my examples and scripts here.

August 2004 - PHP

I demonstrated how to use php for scripting and to write web pages, explained some of the advantages and drawbacks to the language, etc. You can find some of my examples below:

July 2004 - Tunnels

I explained why and what tunnels are used for, some of the problems related to tunnels, and talked about a few different tunnel implementations. You can download my slides below:

August 2003 - Cryptology

This talk covered the basic theory behind cryptography and crypto-analysis. You can download my slides below:

April 2003 - Linux Advanced Routing

Have a look at the following pages for more information about advanced routing in Linux:

March 2003 - Linux Quality of Service

This talk was about using the traffic control and netfilter infrastructure to manage bandwidth more effectively and how to collect statistics to aid with that process.

Unfortunately most of the tools I demonstrated are proprietary (please contact Frogfoot Networks if you need something). For the standard free stuff, you can find lots of very useful documentation, patches and utilities on these pages:

October 2002 - Graphing

This talk was mostly about graphing time based data using the RRD Tool and other utilities/libraries.

Below are some of the material I used to give this talk.

August 2002 - I2C

This talk was about I2C, the serial bus used by most modern PC hardware. Most of the stuff I talked about are documented on the LM Sensors page.

July 2002 - IP Tables

Warwick Duncan did most of the talking at this meeting. I just talked about the concept of private IP ranges and how to do network address translation (NAT). As mentioned in the talk, it all boils down to:

Source NAT

# Change source addresses to 1.2.3.4.
iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 1.2.3.4

# Change source addresses to 1.2.3.4, 1.2.3.5 or 1.2.3.6.
iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 1.2.3.4-1.2.3.6

# Change source addresses to 1.2.3.4, ports 1-1023 iptables -t nat -A POSTROUTING -p tcp -o eth0 -j SNAT --to 1.2.3.4:1-1023

# Masquerade everything out ppp0. You don't need to specify source
# address, connections are forgotten when link goes down.
iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE

Destination NAT

# Send incoming port-80 web traffic to our squid (transparent) proxy
iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-port 3128

If you want to list the NAT rules which you have added, you just use this command:

iptables -L -n -t nat

March 2002 - Linux Embedded Systems

This talk was about Linux based embedded systems. I demonstrated a Linux-based production line camera system.

I have removed my embedded Linux projects page, so you can't view the details about this talk anymore. Please email me if you need anything.

October 2001 - TCP/IP Networking Talks (Lecture 5 of 5)

In case you're wondering what happened to the 5th lecture in this series, it doesn't exist. I forgot about the lecture and Marc Welz gave a small substitute lecture.

October 2001 - TCP/IP Networking Talks (Lecture 4 of 5)

This was the fourth in a series of talks about networking (TCP/IP in particular).

As with the first lecture, I've included some supplementary notes for the second lecture below.

Please do not distribute these lecture notes. I have copied some parts from books (See Reference section in each document) without modification, so the result is therefore not really suitable for distribution.

In the light of this, please do not distribute this document. It is simply intended as supplementary material to the lecture and should only be read by the those who attended the lectures.

Below you can find the notes for the fourth lecture. It is in Postscript format.

September 2001 - TCP/IP Networking Talks (Lecture 3 of 5)

The third lecture in this series was given by Johann Botha. You can find the notes for this lecture on his home page.

For those who didn't attend this lecture: This lecture was about Layer 5 and 6 and not Layer 4 and 5. I'll be giving a lecture on Layer 4 and Layer 7 next time.

The reason why decided to split these two lectures were to try and keep the most technical lecture for last (semi-last actually). It also served to give me a break.

September 2001 - TCP/IP Networking Talks (Lecture 2 of 5)

This was the second in a series of talks about networking (TCP/IP in particular).

As with the first lecture, I've included some supplementary notes for the second lecture below.

Please do not distribute these lecture notes. I have copied some parts from books (See Reference section in each document) without modification, so the result is therefore not really suitable for distribution.

In the light of this, please do not distribute this document. It is simply intended as supplementary material to the lecture and should only be read by the those who attended the lectures.

Below you can find the notes for the second lecture. It is in Postscript format.

August 2001 - TCP/IP Networking Talks (Lecture 1 of 5)

This was the first in a series of talks about networking (TCP/IP in particular).

I'll try to write some supplumentary notes for each lecture which you can use as a reference.

Please do not distribute these lecture notes. I have copied some parts from books (See Reference section in each document) without modification, so the result is therefore not really suitable for distribution.

In the light of this, please do not distribute this document. It is simply intended as supplementary material to the lecture and should only be read by the those who attended the lectures.

Below you can find the notes for the first lecture. It is in Postscript format.

Some people had some problems viewing the notes above. For those people, I've created a revised edition with different fonts. Try this one if the one above doesn't display/print correctly.

July 2001 - X programming

This talk was about graphics programming in X. I briefly covered the differences between SDL, DGA, and xlib.

Below you can find a tarball containing all the example programs I demonstrated during the lecture and also the notes I used for the talk.