"Transmission of IPv6 Packets over Ethernet Networks" ([RFC2464],
Section 7) specifies how an IPv6 packet with a multicast destination
address is mapped into an Ethernet link-layer address. This document
extends this mapping to explicitly allow for a mapping of an IPv6
packet with a multicast destination address into an Ethernet link-
layer unicast address, when it is clear that only one address is
This mapping does not replace the mapping described in [RFC2464],
Section 7. The determination of the unicast Ethernet link-layer
address and the construction of the outgoing IPv6 packet are out of
scope for this document.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
An IPv6 node receiving an IPv6 packet with a multicast destination
address and an Ethernet link-layer unicast address MUST NOT drop the
packet as a result of the use of this form of address mapping.
This document does not introduce any new security vulnerabilities.
The authors would like to acknowledge Bernard Aboba, Fred Baker, Wes
Beebee, Ron Bonica, Olaf Bonness, Jean-Michel Combes, Ralph Droms,
Alain Durand, Suresh Krishnan, Eric Levy-Abegnoli, Phil Roberts,
Behcet Sarikaya, Hemant Singh, Mark Smith, Dave Thaler, Pascal
Thubert, Stig Venaas, and Eric Voit for their contributions and
discussions on this topic.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet
Networks", RFC 2464, December 1998.