--add-mac[=base64|text]
Add the MAC address of the requestor to DNS queries which are
forwarded upstream. This may be used to DNS filtering by the upstream
server. The MAC address can only be added if the requestor is on the same
subnet as the dnsmasq server. Note that the mechanism used to achieve this (an EDNS0 option)
is not yet standardised, so this should be considered
experimental. Also note that exposing MAC addresses in this way may
have security and privacy implications. The warning about caching
given for --add-subnet applies to --add-mac too. An alternative encoding of the
MAC, as base64, is enabled by adding the "base64" parameter and a human-readable encoding of hex-and-colons is enabled by added the "text" parameter.