Network Diagramming Software, FREE or Open-Source [closed]

Dia is a such program. DiaCze is a windows only version packaged with icon for network diagramming (but you can extract content on a windows computer and copy it to a unix system).

Edit: I discovered Kivio today, a Visio like (but still in development)

Dia (http://projects.gnome.org/dia/) is the preeminent free opensource diagramming software. It's also pretty ugly.

If you're on a mac, I recommend Omnigraffle (http://www.omnigroup.com/applications/OmniGraffle/). It's my favorite diagramming software on any platform. It's neither free nor open source.

There are also online tools that actually look pretty good. My favorite so far is Gliffy: http://www.gliffy.com/

Your question doesn't specify you need a fancy GUI, so I'm going to suggest GraphViz (http://www.graphviz.org/)

With graphviz can define your nodes and connection in a text file and use the command line to generate the graph in a number of different output formats.

Its no Visio but it often does the job for me.

On linux I have used Dia. It is certainly the standard, but it is also ugly as sin. Lacking Visio, which is excellent for diagramming, I have used OpenOffice Draw. Since it is both free and open-source, I would recommend looking into it first.

YED Graph Editor should fulfill your needs. It is easy to use! Have a look at it.