-y, --localise-queries
Return answers to DNS queries from /etc/hosts and --interface-name and --dynamic-host which depend on the interface over which the query was received. If a name has more than one address associated with it, and at least one of those addresses is on the same subnet as the interface to which the query was sent, then return only the address(es) on that subnet and return all the available addresses otherwise. This allows for a server to have multiple addresses in /etc/hosts corresponding to each of its interfaces, and hosts will get the correct address based on which network they are attached to. Currently this facility is limited to IPv4.