Internet Engineering Task Force (IETF) S. Gundavelli
Request for Comments: 6085 M. Townsley
Updates: 2464 O. Troan
Category: Standards Track W. Dec
ISSN: 2070-1721 Cisco
Address Mapping of IPv6 Multicast Packets on Ethernet
When transmitting an IPv6 packet with a multicast destination
address, the IPv6 destination address is mapped to an Ethernet link-
layer multicast address. This document clarifies that a mapping of
an IPv6 packet with a multicast destination address may in some
circumstances map to an Ethernet link-layer unicast address.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Gundavelli, et al. Standards Track [Page 1]RFC 6085 Unicast Transmission on Link Layer January 20111. Introduction
"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].
3. Receiving IPv6 Multicast Packets
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.
4. Security Considerations
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.
6. Normative References
[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.
Gundavelli, et al. Standards Track [Page 2]RFC 6085 Unicast Transmission on Link Layer January 2011Authors' Addresses
170 West Tasman Drive
San Jose, CA 95134