http://www.rfc-editor.org/rfc/rfc6939.txt
RFC 6939: Client Link-Layer Address Option in DHCPv6, G. Halwasia, S. Bhandari, W. Dec2013-05-01T23:00:00-00:00This document specifies the format and mechanism that is to be used for encoding the client link-layer address in DHCPv6 Relay-Forward messages by defining a new DHCPv6 Client Link-Layer Address option.