Visual Network Simulator To Teach Basic Networking?

unteer writes "I am a US Peace Corps volunteer currently teaching a computer technician course at a technical college in Kenya. My students have all completed the Kenyan equivalent of high school and have been accepted into a program where they give a year of nation-building non-military service in return for a technical education. My students' course load includes an introduction to computer networking, and this is where my problem lies. Do any of you know of a visual network simulator that can create an interactive network map that allows me, the instructor, to manipulate various components of a network, including the physical media, routing configuration, and which applications are being used to submit data? An example would be to have a visual of the differences between mail traffic and web traffic, and be able to show how the configuration of a wireless network might be different from a wired network. I know this may seem silly, but visuals of all this are critical to getting ideas across. It doesn't even have to be technically accurate, but rather just pictorially accurate, possibly just labeling the various components correctly. Also, it would be highly preferable if it ran on Linux, as I teach using FOSS only."

Re:You have a problem

[Anonymous Coward]

Do we really wanna teach Kenyans about the internet? Look how well the Nigerians have done with such knowledge... And to counter your sig, I'm a 140k+ sysadmin without a diploma or a bookshelf, and I'm damn good at my job.