yED is an alternative software for those engineers who are working with linux and dont like microsoft visio and want make network topologies faster and simplier for free :-)
There is a lot of features like automatic layout and easy data import and so on it realy intuitive when you use it. One of the biggest advantage is that you can automate the creation of a graph with scripting languages.
Link 1.: https://www.yworks.com/products/yed/applicationfeatures
Link 2.: https://www.yworks.com/products/yed
Install on Linux is easy:
download your version and let it install itself:
chmod +x yEd-3.16.1_64-bit_setup.sh sudo sh yEd-3.16.1_64-bit_setup.sh
Here you can find 2 network topology example. those have the icons you may need for your own topology:
To import a stencil goto Edit -> Manage Palette -> Import Section…
OSA (Open Security Architecture) stencils
Palo Alto stencils
Cisco network stencils
Those are not easily import to yED since their format is currently not supported, but importing only the uniq stencil tha you need is not a big deal.