As I wanted to play with etherboot, pxe boot and like I needed a dhcp server that I could control and take on and offline as seen fit. That ruled out the normal dhcp server we have on our network. What to do? Create one inside a kvm and block all network traffic from and to it from outside.
Little description of the network setup.
eth0 is the interface to the wide world aka local network
each vm has a tap device with naming like tap-$name_of_vm0
They all are joined...
