I have configured a DHCP server on Ubuntu and a fixed IP address for a specific mac, like this:
host client1 {
hardware ethernet E0:69:95:73:2C:66;
fixed-address 192.168.0.10;
}
If anyone changes his/her mac to E0:69:95:73:2C:66
, they get the 192.168.0.10 IP and now two PCs use the Internet simultaneously on the same IP. How can I protect against this unauthorized access?