I’ve been attempting to put effort towards network documentation at work, with the intention of accurate maps for LAN and WAN connectivity.
Microsoft Visio is the first product that comes to mind for this purpose, however it comes with a licensing cost. Here are two alternatives I’ve used:
yED
http://www.yworks.com/products/yed
Right now this is my product of choice; it is fully featured with no limitations, comes with a large amount of icons and shapes for use, and has the ability to import many more.
Using it is very intuitive and quick to pick up.
LucidChart
This web service produces very nice looking drawings, with an easy to use interface and great organization of drawings. It comes with icons and shapes from some of the big brands like AWS and Cisco.
The only reason I moved on from this is that the free tier only allows a specific number of drawings, with a small number of objects each. This limitation proved too great to continue using.