man ethers (Formats) - Ethernet address to IP number database
NAME
ethers - Ethernet address to IP number database
DESCRIPTION
/etc/ethers contains 48 bit Ethernet addresses and their corresponding IP numbers, one line for each IP number: Ethernet-address IP-number The two items are separated by any number of SPACE and/or TAB characters. A # at the beginning of a line starts a comment which extends to the end of the line. The Ethernet-address is written as x:x:x:x:x:x, where x is a hexadecimal number between 0 and ff which represents one byte of the address, which is in network byte order (big-endian). The IP-number may be a hostname which can be resolved by DNS or a dot separated number.
EXAMPLES
08:00:20:00:61:CA pal
FILES
/etc/ethers