You can use arping to know IP address to MAC address mapping of your local network. Usage is simple:
arping [-AbDfhqUV] [-c count] [-w deadline] [-s source] -I interface destination For example, you may use the command as below:
$ arping -I eth0 10.0.0.1 ARPING 10.0.0.1 from 10.0.0.2 eth0 Unicast reply from 10.0.0.1 [11:22:33:44:55:66] 0.123ms Unicast reply from 10.0.0.1 [11:22:33:44:55:66] 0.251ms ... Secret of the tool is ARP protocol [1]. To know the MAC address of the machine that has a specific IP address, IP protocol layer uses the protocol.