Here is the real scenario. I have say 4 machines not having any IP address yet connected to a switch. In one of the machines (OS=CentOS), I would install a DHCP server and would provide the other machines IP addresses. Prior to assigning them IP addresses, I need to get the MAC address of each of the machines that I would assign IP addresses to. So, my question here is how to I get the MAC addresses of all the machines connected to a switch when NO machine has got any IP address yet? It's mandatory for my use case that I won't be having any IP addresses before the MAC addresses. -Thanks