Dia Drawing Program

From their website:

Dia is roughly inspired by the commercial Windows program 'Visio', though more geared towards informal diagrams for casual use. It can be used to draw many different kinds of diagrams. It currently has special objects to help draw entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and many other diagrams. It is also possible to add support for new shapes by writing simple XML files, using a subset of SVG to draw the shape.

It can load and save diagrams to a custom XML format (gzipped by default, to save space), can export diagrams to a number of formats, including EPS, SVG, XFIG, WMF and PNG, and can print diagrams (including ones that span multiple pages).

http://live.gnome.org/Dia

Network Security: Free Tools

Greetings and Salutations!

Today I am going to be introducing the popular network scanning tool, Nmap.

Nmap allows one to 'map' an entire network by scanning ports (both TCP & UDP),  performing operating system detection, ping sweeps and more.

This allows for a network administrator to determine the relative security of their lan; by detecting the state of all ports on a specific target.  Nmap will even give hints as to what certain ports are primarily used for.

Here is a sample input and what to expect as an output:

nmap -sS -vv 192.168.0.0/24

This command will  perform a TCP SYN (-sS) scan of the entire 192.168.0 network, with two levels of verbosity. (-vv)

As a result the administrator would know which TCP ports are open on all hosts, and the services associate with said port.  This is just a small sample of the power of Nmap, which like all network tools, should be used for the purposes of good, not evil.

-Chris

keybr.com

keybr.com is a nifty site that provides a flash-based on-screen keyboard to help improve typing skills.

The thing that I really like about keybr.com is how each key is color-coded to show how well you are typing that particular letter. The keys that need practice turn a darker shade of red, while the keys that are hit correctly are shaded green. Well worth a try to at the very least find the weaknesses in your typing style.