48-bit Extended Unique Identifier (EUI-48) and 64-bit Extended Unique
Identifier (EUI-64) are address formats specified by the IEEE for use
in various layer-2 networks, e.g., Ethernet.
This document describes two new DNS resource record types, EUI48 and
EUI64, for encoding Ethernet addresses in the DNS.
This document describes potentially severe privacy implications
resulting from indiscriminate publication of link-layer addresses in
the DNS. EUI-48 or EUI-64 addresses SHOULD NOT be published in the
public DNS. This document specifies an interoperable encoding of
these address types for use in private DNS namespaces, where the
privacy concerns can be constrained and mitigated.