Finally, UML makes a fine tool for creating virtual networks. This is good for observing worms and viruses. The virtual network is easy to create and shut down, lightweight in its use of host resources.
It is scriptable, so networks can be created, controlled, and shut down automatically.
UML virtual networks can be completely isolated from the host and the physical network, so there is no chance that a worm or virus that's being observed can escape into the outside world.