A Free network/Un managed network, means anyone can transfer any packets with any SRC MAC address. the network admin should consider upgrade the hardware if at all. an unmanaged network switch has another name: HUB. HUB at it's nature it is just a connection of 8 line of wires into all connected ports , it connected all NIC into one media, every packet is a boardcast, and everyone can hear anyone talk :) .Imaging you sit inside a supermarket , or some political community party in TAIWAN/South Korea, that's HUB way of communication.
Obviously There are many disadvantage of HUB beside it's real purpose : connect NIC at Layer 2. If you are network admin, please treat this message as something you need spend effort to improve ASAP.
Solution one: netcut-defender
Solution two: managed swith
Solution Three: For wireless AP, should install netcut-defender on AP node directly.
consolute at http://www.arcai.com/bbs.html