# make the data a string
$value = join("|", $VLAN, $MAC, $INT);

# put them into a 1 dimentional hash (however, servers with the same mac hash overwrite each other, although you can check)
if( defined $HASH{$mac} ) {
 warn "Two servers with the same $mac";
}else{
 $HASH{$mac}=$value; 
}