Unfortunately I recursively face the problem of creating network diagrams in linux. There are a lot of options (as usual in linux) for this:
- Dia: Quite good, lot of resources there but... a bit ugly result from my point of view.
- Inkscape: You can achieve very good results but... it is a vectorial drawing program and it is not fast.
- Online: I won't (will not!) use an online tool for that.
In M$ people use Visio and the results are awesome with a scarce amount of effort. Why can't I have that in linux? Simple answer, you can.
You can use libreoffice draw and add galleries to it. In particular there is http://extensions.libreoffice.org/extension-center/vrt-network-equipment/ which has a vectorial gallery of network resources which is perfect for fast, nice looking network diagrams. You just have to go to "Tools --> Extension Manager" and install the file you can download from the link. Then in your draw sheet go to "Insert --> Media --> Clip Art Gallery" and a new tab will appear where you will see the VRT resources.