Ethernet simulator for learning
I wrote an Ethernet simulator. The main purpose for this development is leaning Ethernet by my students in Kogakuin University. This program is in public domain.
There are simulators that exactly simulates Ethernet networks, but I could not find an appropriate simulator for educational purposes, so I wrote one by myself. You can open multiple command windows and each window can run this program to simulate a switch or a terminal. It is a very simple program, so there are restrictions such as the port number range. However, you can roughly see mechanisms of Ethernet network.