Graphical Network Simulator-3 (GNS3) - Part I Initial Introduction on a Laptop

Someone told me about this network modeling and simulation tool called Graphical Network Simulator-3. There is a Wikipedia page on this tool, which can be found here:

https://en.wikipedia.org/wiki/Graphical_Network_Simulator-3

Fascinating tool. Allows you to drag and drop network elements onto a canvas - but unlike the old tools, this tool can actually RUN the elements! To do this, you need to import image files as you drag and drop the elements out on the canvas. Below is an example of how, when dragging a simulated internet cloud onto the canvas will prompt for an image to run on a virtual machine.

Image Files Required for Network Elements in GNS3

Then, once you have the elements properly situated on the canvas, you can use a connector to interconnect them (it will prompt you for the NIC interface), and then, once your interconnection points are established, you can click a "run" button.

If all goes well everything turns green and packets start to flow. There is a built-in packet trace on each link line, which will dump packets to a file if you choose to do a packet capture.