What do colors mean in the Network Mapper?
As you probably noticed, computers are represented as spheres and connections between them as lines. Take a closer look at the spheres. If they are solid, this means the corresponding computer answered our status request. Sometimes, computers do not answer for several reasons like network congestion, or a version lower than 0.827. In these cases, we know that these computers exist through the other nodes that answered our status request. These nodes are plotted as wire spheres (from far away, wire spheres seem gray). Now the meaning of colors is related to the number of computations a computer is currently performing (green = 0, blue = 1, violet = 2, red = 3). Sometimes, computers answer with a wrong IP (they have a dynamic IP). This confuses the Network Mapper: several gray wire spheres appear. We call these spheres ghosts, because they do not represent a computer.
