cnet is a network simulator which enables experimentation with various data-link layer, network layer, routing and transport layer networking protocols in networks consisting of any combination of wide-area-networking (WAN), local-area-networking (LAN), or wireless-local-area-networking (WLAN) links.cnet either displays the entire network simulation 'map' under Tcl/Tk or runs rather less visually on an ASCII terminal. Under Tcl/Tk, cnet provides a graphical representation of the network under execution and permits a number of attributes of the network to be modified while the simulation is running. Nodes may be selected with the mouse to reveal a sub-window displaying the output and protocol statistics of that node. Some of the node's attributes, such as message generation rates and sizes, may be modified using checkboxes and sliders. Similarly, the default attributes of all nodes in the network may be simultaneously modified by selecting and changing global attributes. From another menu, each node may be forced to reboot, (impolitely) crash, (politely) shutdown and reboot, pause and (hardware) fail.cnet has been specifically developed at The University of Western Australia for undergraduate computer networking courses taken by thousands of students worldwide since 1991 (latest release March 2014).