Can you tell me where I can create nice maps that I can use as background image for PRTG's Maps function. I would prefer free online services.
Where can I create charts and plans online for use with PRTG's Maps feature?
Four Free and Quick Ways to Create Beautiful Network Maps Online
In order to make the results of your network monitoring available in your Intranet or for customers we recommend using the Maps feature of PRTG Network Monitor in conjunction with a map of your network. Visualized results make it much easier for your users to understand the situation of your network.
But how do you create a map of your network? There are paid-for options, e.g. Microsoft Visio, and other programs that you must install locally on your computer. But in many cases using one of the following free online options may serve you well for a quick map!
http://www.lovelycharts.com offers a flash based online tool for creation of diagrams, flowcharts and network maps. With their free account you can create one map and they look pretty. There is an extensive list of network objects, connections are sticky (i.e. the re-arrange when you move the objects) and you can enter a label for each object. When your are done with the creation you can export the map as JPG or PNG file. It's my personal favorite on this list.
http://www.gliffy.com also is a flash based online chart editor which offers a free 30 day trial and a free account. Gliffy offers a very good selection of network objects (even rack elements), connections are sticky and you can enter a label for objects. Maps can be exported as PDF, JPG or PNG. Note: For the free account your charts will be publicly visible!
#4: www.imaginationcubed.com by General Electric
Imagination Cubed offered by General Electric does not offer a library of network objects, it is mostly a free-hand drawing tool - but it offers nice add-on: You can invite one or more other persons to join your whiteboard and create the drawing together with you.