draft-ietf-6man-multicast-addr-arch-update-05.txt   draft-ietf-6man-multicast-addr-arch-update-06.txt 
6man Working Group M. Boucadair 6man Working Group M. Boucadair
Internet-Draft France Telecom Internet-Draft France Telecom
Updates: 3306,3956,4291 (if approved) S. Venaas Updates: 3306,3956,4291 (if approved) S. Venaas
Intended status: Standards Track Cisco Intended status: Standards Track Cisco
Expires: December 20, 2014 June 18, 2014 Expires: January 5, 2015 July 04, 2014
Updates to the IPv6 Multicast Addressing Architecture Updates to the IPv6 Multicast Addressing Architecture
draft-ietf-6man-multicast-addr-arch-update-05 draft-ietf-6man-multicast-addr-arch-update-06
Abstract Abstract
This document updates the IPv6 multicast addressing architecture by This document updates the IPv6 multicast addressing architecture by
re-defining the reserved bits as generic flag bits. The document re-defining the reserved bits as generic flag bits. The document
provides also some clarifications related to the use of these flag provides also some clarifications related to the use of these flag
bits. bits.
This document updates RFC 3956, RFC 3306 and RFC 4291. This document updates RFC 3956, RFC 3306 and RFC 4291.
skipping to change at page 1, line 42 skipping to change at page 1, line 42
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 20, 2014. This Internet-Draft will expire on January 5, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Addressing Architecture Update . . . . . . . . . . . . . . . 2 2. Addressing Architecture Update . . . . . . . . . . . . . . . 3
3. Flag Bits: A Recommendation . . . . . . . . . . . . . . . . . 3 3. Flag Bits: A Recommendation . . . . . . . . . . . . . . . . . 3
4. RFC Updates . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. RFC Updates . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. RFC 3306 . . . . . . . . . . . . . . . . . . . . . . . . 3 4.1. RFC 3306 . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1.1. Update #1 . . . . . . . . . . . . . . . . . . . . . . 4
4.1.2. Update #2 . . . . . . . . . . . . . . . . . . . . . . 5
4.2. RFC 3956 . . . . . . . . . . . . . . . . . . . . . . . . 6 4.2. RFC 3956 . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2.1. Update #1 . . . . . . . . . . . . . . . . . . . . . . 6
4.2.2. Update #2 . . . . . . . . . . . . . . . . . . . . . . 6
4.2.3. Update #3 . . . . . . . . . . . . . . . . . . . . . . 8
4.2.4. Update #4 . . . . . . . . . . . . . . . . . . . . . . 8
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
8. Normative References . . . . . . . . . . . . . . . . . . . . 8 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction 1. Introduction
This document updates the IPv6 addressing architecture [RFC4291] by This document updates the IPv6 addressing architecture [RFC4291] by
re-defining reserved bits as generic flag bits (Section 2). The re-defining reserved bits as generic flag bits (Section 2). The
document provides also some clarifications related to the use of document provides also some clarifications related to the use of
these flag bits (Section 3). these flag bits (Section 3).
This document updates [RFC3956], [RFC3306], and [RFC4291]. These This document updates [RFC3956], [RFC3306], and [RFC4291]. These
skipping to change at page 3, line 9 skipping to change at page 3, line 20
they apply to any multicast address. These bits are referred to as they apply to any multicast address. These bits are referred to as
ff2 (flag field 2) while the flgs bits in [RFC4291][RFC3956] are ff2 (flag field 2) while the flgs bits in [RFC4291][RFC3956] are
renamed to ff1 (flag field 1). renamed to ff1 (flag field 1).
Within this document, flag bits denote both ff1 and ff2. Within this document, flag bits denote both ff1 and ff2.
Defining the bits 17-20 as flags for all IPv6 multicast addresses Defining the bits 17-20 as flags for all IPv6 multicast addresses
allows addresses to be treated in a more uniform and generic way, and allows addresses to be treated in a more uniform and generic way, and
allows for these bits to be defined in the future for different allows for these bits to be defined in the future for different
purposes, irrespective of the specific type of multicast address. purposes, irrespective of the specific type of multicast address.
For the record, this design choice was initially triggered by
specification in [I-D.ietf-mboned-64-multicast-address-format] which
proposed for associating a meaning with one of the reserved bits.
Moreover, [I-D.ietf-mboned-64-multicast-address-format] considered
also the use of the last remaining flag in ff1 but that approach was
abandoned because it is not clear at this stage whether there is
other usage scenarios of the flag.
Section 4 specifies the updated structure of the addressing Section 4 specifies the updated structure of the addressing
architecture. architecture.
Further specification documents may define a meaning for these flag Further specification documents may define a meaning for these flag
bits. bits.
3. Flag Bits: A Recommendation 3. Flag Bits: A Recommendation
Some implementations and specification documents do not treat the Some implementations and specification documents do not treat the
flag bits as separate bits but tend to use their combined value as a flag bits as separate bits but tend to use their combined value as a
4-bit integer. This practice is a hurdle for assigning a meaning to 4-bit integer. This practice is a hurdle for assigning a meaning to
the remaining flag bits. Below are listed some examples for the remaining flag bits. Below are listed some examples for
illustration purposes: illustration purposes:
o the reading of [RFC3306] may lead to conclude that ff3x::/32 is o the reading of [RFC3306] may lead to conclude that ff3x::/32 is
the only allowed SSM IPv6 prefix block. the only allowed Source Specific Multicast (SSM) IPv6 prefix
block.
o [RFC3956] states only ff70::/12 applies to Embedded-RP. o [RFC3956] states only ff70::/12 applies to Embedded-RP.
Particularly, implementations should not treat the fff0::/12 range Particularly, implementations should not treat the fff0::/12 range
as Embedded-RP. as Embedded-RP.
To avoid such confusion and to unambiguously associate a meaning with To avoid such confusion and to unambiguously associate a meaning with
the remaining flags, the following requirement is made: the remaining flags, the following requirement is made:
Implementations MUST treat flag bits as separate bits. Implementations MUST treat flag bits as separate bits.
4. RFC Updates 4. RFC Updates
4.1. RFC 3306 4.1. RFC 3306
4.1.1. Update #1
This document changes Section 4 of [RFC3306] as follows: This document changes Section 4 of [RFC3306] as follows:
OLD: OLD:
| 8 | 4 | 4 | 8 | 8 | 64 | 32 | | 8 | 4 | 4 | 8 | 8 | 64 | 32 |
+--------+----+----+--------+--------+----------------+----------+ +--------+----+----+--------+--------+----------------+----------+
|11111111|flgs|scop|reserved| plen | network prefix | group ID | |11111111|flgs|scop|reserved| plen | network prefix | group ID |
+--------+----+----+--------+--------+----------------+----------+ +--------+----+----+--------+--------+----------------+----------+
+-+-+-+-+ +-+-+-+-+
skipping to change at page 4, line 26 skipping to change at page 4, line 38
address as defined in [ADDRARCH]. address as defined in [ADDRARCH].
o P = 1 indicates a multicast address that is assigned based o P = 1 indicates a multicast address that is assigned based
on the network prefix. on the network prefix.
o If P = 1, T MUST be set to 1, otherwise the setting of the T o If P = 1, T MUST be set to 1, otherwise the setting of the T
bit is defined in Section 2.7 of [ADDRARCH]. bit is defined in Section 2.7 of [ADDRARCH].
The reserved field MUST be zero. The reserved field MUST be zero.
Note: [ADDRARCH] is a reference listed in [RFC3306]. [ADDRARCH]
has been since obsoleted by [RFC4291].
NEW: NEW:
| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 | | 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
+--------+----+----+----+----+--------+----------------+----------+ +--------+----+----+----+----+--------+----------------+----------+
|11111111|ff1 |scop|ff2 |rsvd| plen | network prefix | group ID | |11111111|ff1 |scop|ff2 |rsvd| plen | network prefix | group ID |
+--------+----+----+----+----+--------+----------------+----------+ +--------+----+----+----+----+--------+----------------+----------+
+-+-+-+-+ +-+-+-+-+
ff1 (flag field 1) is a set of 4 flags: |X|Y|P|T| ff1 (flag field 1) is a set of 4 flags: |X|Y|P|T|
+-+-+-+-+ +-+-+-+-+
skipping to change at page 5, line 31 skipping to change at page 5, line 31
on the network prefix. on the network prefix.
o If P = 1, T MUST be set to 1, otherwise the setting of the T o If P = 1, T MUST be set to 1, otherwise the setting of the T
bit is defined in Section 2.7 of [RFC4291]. bit is defined in Section 2.7 of [RFC4291].
+-+-+-+-+ +-+-+-+-+
ff2 (flag field 2) is a set of 4 flags: |r|r|r|r| ff2 (flag field 2) is a set of 4 flags: |r|r|r|r|
+-+-+-+-+ +-+-+-+-+
where "rrrr" are for future assignment as additional flag bits. where "rrrr" are for future assignment as additional flag bits.
r bits MUST each be set to 0.
Flag bits denote both ff1 and ff2. Flag bits denote both ff1 and ff2.
4.1.2. Update #2
This document changes Section 6 of [RFC3306] as follows: This document changes Section 6 of [RFC3306] as follows:
OLD: OLD:
These settings create an SSM range of FF3x::/32 (where 'x' is any These settings create an SSM range of FF3x::/32 (where 'x' is any
valid scope value). The source address field in the IPv6 header valid scope value). The source address field in the IPv6 header
identifies the owner of the multicast address. identifies the owner of the multicast address.
NEW: NEW:
If the flag bits in ff1 are set to 0011, these settings create an If the flag bits in ff1 are set to 0011, these settings create an
SSM range of ff3x::/32 (where 'x' is any valid scope value). The SSM range of ff3x::/32 (where 'x' is any valid scope value). The
source address field in the IPv6 header identifies the owner of source address field in the IPv6 header identifies the owner of
the multicast address. ff3x::/32 is not the only allowed SSM the multicast address. ff3x::/32 is not the only allowed SSM
prefix range. For example if the most significant flag bit in ff1 prefix range. For example if the most significant flag bit in ff1
is set, then we would get the SSM range ffbx::/32. is set, then we would get the SSM range ffbx::/32.
4.2. RFC 3956 4.2. RFC 3956
4.2.1. Update #1
This document changes Section 2 of [RFC3956] as follows: This document changes Section 2 of [RFC3956] as follows:
OLD: OLD:
As described in [RFC3306], the multicast address format is as As described in [RFC3306], the multicast address format is as
follows: follows:
| 8 | 4 | 4 | 8 | 8 | 64 | 32 | | 8 | 4 | 4 | 8 | 8 | 64 | 32 |
+--------+----+----+--------+----+----------------+----------+ +--------+----+----+--------+----+----------------+----------+
|11111111|flgs|scop|reserved|plen| network prefix | group ID | |11111111|flgs|scop|reserved|plen| network prefix | group ID |
skipping to change at page 6, line 41 skipping to change at page 6, line 43
+-+-+-+-+ +-+-+-+-+
ff1 (flag field 1) is a set of four flags: |X|R|P|T| ff1 (flag field 1) is a set of four flags: |X|R|P|T|
+-+-+-+-+ +-+-+-+-+
X may be set to 0 or 1. X may be set to 0 or 1.
+-+-+-+-+ +-+-+-+-+
ff2 (flag field 2) is a set of 4 flags: |r|r|r|r| ff2 (flag field 2) is a set of 4 flags: |r|r|r|r|
+-+-+-+-+ +-+-+-+-+
where "rrrr" are for future assignment as additional flag bits. where "rrrr" are for future assignment as additional flag bits.
r bits MUST each be set to 0.
Flag bits denote both ff1 and ff2. Flag bits denote both ff1 and ff2.
4.2.2. Update #2
This document changes Section 3 of [RFC3956] as follows: This document changes Section 3 of [RFC3956] as follows:
OLD: OLD:
| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 | | 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
+--------+----+----+----+----+----+----------------+----------+ +--------+----+----+----+----+----+----------------+----------+
|11111111|flgs|scop|rsvd|RIID|plen| network prefix | group ID | |11111111|flgs|scop|rsvd|RIID|plen| network prefix | group ID |
+--------+----+----+----+----+----+----------------+----------+ +--------+----+----+----+----+----+----------------+----------+
+-+-+-+-+ +-+-+-+-+
flgs is a set of four flags: |0|R|P|T| flgs is a set of four flags: |0|R|P|T|
skipping to change at page 7, line 40 skipping to change at page 7, line 40
| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 | | 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
+--------+----+----+----+----+----+----------------+----------+ +--------+----+----+----+----+----+----------------+----------+
|11111111|ff1 |scop|ff2 |RIID|plen| network prefix | group ID | |11111111|ff1 |scop|ff2 |RIID|plen| network prefix | group ID |
+--------+----+----+----+----+----+----------------+----------+ +--------+----+----+----+----+----+----------------+----------+
+-+-+-+-+ +-+-+-+-+
ff1 is a set of four flags: |X|R|P|T| ff1 is a set of four flags: |X|R|P|T|
+-+-+-+-+ +-+-+-+-+
X may be set to 0 or 1. X may be set to 0 or 1.
R = 1 indicates a multicast address that embeds the address of the R = 1 indicates a multicast address that embeds the address of the
RP. P MUST be set to 1, and consequently T MUST be set to 1, RP. Then P MUST be set to 1, and consequently T MUST be set to 1,
according to [RFC3306], as this is a special case of unicast-prefix according to [RFC3306], as this is a special case of unicast-prefix
based addresses. This implies that for instance prefixes ff70::/12 based addresses. This implies that, for instance, prefixes ff70::/12
and fff0::/12 are embedded RP prefixes. The behavior is unspecified and fff0::/12 are embedded RP prefixes. The behavior is unspecified
if P or T is not set to 1. When the R-bit is set, the last 4 bits of if P or T is not set to 1. When the R-bit is set, the last 4 bits of
the field that were reserved in [RFC3306] are interpreted as the field that were reserved in [RFC3306] are interpreted as
embedding the RP interface ID, as specified in this memo. embedding the RP interface ID, as specified in this memo.
4.2.3. Update #3
This document changes Section 4 of [RFC3956] as follows: This document changes Section 4 of [RFC3956] as follows:
OLD: OLD:
It MUST be a multicast address with "flgs" set to 0111, that is, It MUST be a multicast address with "flgs" set to 0111, that is,
to be of the prefix FF70::/12, to be of the prefix FF70::/12,
NEW: NEW:
It MUST be a multicast address with R-bit set to 1. It MUST be a multicast address with R-bit set to 1.
It MUST have P-bit and T-bit both set to 1 when using the It MUST have P-bit and T-bit both set to 1 when using the
embedding in this document as it is a prefix-based address. embedding in this document as it is a prefix-based address.
4.2.4. Update #4
This document changes Section 7.1 of [RFC3956] as follows: This document changes Section 7.1 of [RFC3956] as follows:
OLD: OLD:
To avoid loops and inconsistencies, for addresses in the range To avoid loops and inconsistencies, for addresses in the range
FF70::/12, the Embedded-RP mapping MUST be considered the longest FF70::/12, the Embedded-RP mapping MUST be considered the longest
possible match and higher priority than any other mechanism. possible match and higher priority than any other mechanism.
NEW: NEW:
To avoid loops and inconsistencies, for addresses with R-bit set To avoid loops and inconsistencies, for addresses with R-bit set
to 1, the Embedded-RP mapping MUST be considered the longest to 1, the Embedded-RP mapping MUST be considered the longest
possible match and higher priority than any other mechanism. possible match and higher priority than any other mechanism.
5. IANA Considerations 5. IANA Considerations
This document does not require any action from IANA. This document does not require any action from IANA.
6. Security Considerations 6. Security Considerations
Security considerations discussed in [RFC3956], [RFC3306] and The same security considerations as those discussed in [RFC3956],
[RFC4291] MUST be taken into account. [RFC3306] and [RFC4291] are to be taken into account.
7. Acknowledgements 7. Acknowledgements
Special thanks to Brian Haberman for the discussions prior to the Special thanks to Brian Haberman for the discussions prior to the
publication of this document. publication of this document.
Many thanks to Jouni Korhonen and Tatuya Jinmei their review. Many thanks to Jouni Korhonen, Tatuya Jinmei, Charlie Kaufman, and
Ben Campbell for their review.
8. Normative References 8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3306] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6 [RFC3306] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6
Multicast Addresses", RFC 3306, August 2002. Multicast Addresses", RFC 3306, August 2002.
[RFC3956] Savola, P. and B. Haberman, "Embedding the Rendezvous [RFC3956] Savola, P. and B. Haberman, "Embedding the Rendezvous
Point (RP) Address in an IPv6 Multicast Address", RFC Point (RP) Address in an IPv6 Multicast Address", RFC
3956, November 2004. 3956, November 2004.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, February 2006. Architecture", RFC 4291, February 2006.
[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6 [RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
Address Text Representation", RFC 5952, August 2010. Address Text Representation", RFC 5952, August 2010.
8.2. Informative References
[I-D.ietf-mboned-64-multicast-address-format]
Boucadair, M., Qin, J., Lee, Y., Venaas, S., Li, X., and
M. Xu, "IPv6 Multicast Address With Embedded IPv4
Multicast Address", draft-ietf-mboned-64-multicast-
address-format-05 (work in progress), April 2013.
Authors' Addresses Authors' Addresses
Mohamed Boucadair Mohamed Boucadair
France Telecom France Telecom
Rennes 35000 Rennes 35000
France France
Email: mohamed.boucadair@orange.com Email: mohamed.boucadair@orange.com
Stig Venaas Stig Venaas
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