попробуйте ввести "man arp" в терминал. Примерно так может работать:
arp -s hostname ether_addr
Create an ARP entry for the host called hostname with the Ethernet address ether_addr. The Ethernet address is
given as six hex bytes separated by colons. The entry will be permanent unless the word temp is given in the
command. If the word pub is given, the entry will be ``published''; i.e., this system will act as an ARP server,
responding to requests for hostname even though the host address is not its own. In this case the ether_addr can
be given as auto in which case the interfaces on this host will be examined, and if one of them is found to
occupy the same subnet, its Ethernet address will be used. If the only keyword is also specified, this will cre-
ate a ``published (proxy only)'' entry. This type of entry is created automatically if arp detects that a rout-
ing table entry for hostname already exists.