What application can I use to make network diagrams?

I know there are tools like dia, but I'd like it to be more detailed, for example, if I add a switch with 24 ports, I'd like to keep track of the connections on each port instead of a generic line between two components. Do I explain myself?

Thanks in advance?

Must be a really really small network if you can actually put a line to every single switch port.. I didn't even do that when I was using Visio. the drawing would have been so cluttered it would have been indecipherable.

Dia
tgif
tkined
kivio
xfig
graphviz

Really any of the tools could do what you want if you have the proper stencils to begin with.. That's where visio excels. since a lot of manufacturers publish visio stencils for there equipment. Including stencils that show all the ports and modules..

Some people have worked on importing those stencils into programs for Linux.
http://www.redferni.uklinux.net/visio/
http://www.redferni.uklinux.net/dia/vdx/

http://freshmeat.net/projects/vsdump/
http://www.gnome.ru/fileformats/visio_intro.html