kivio seems like a good opensource tool to make diagrams. i found already a lot of stencils for cisco devices. in the next days i will probably make some diagrams and document my work. this is probably also an very important thing to do. just to not forget what i have done. to write down everything i do.
as i use linux as my favorite operating system now for about 10 years, i try to find other applications so i don’t have to use for example visio, which is quite expensive, when needed for private use only. so this is a very good alternativ, on what i have seen so far. also it seems to be a little bit similar to visio.
It possible to export into many different picture formats as for example jpg, gif and bmp.
Cisco’s ConfigMaker might be also a nice tool to create a diagram. But it’s limited to a relativly small number of routers and there are no switches included. But yo can also export diagrams with the programm.