draft-ietf-mboned-ssm232-06.txt   draft-ietf-mboned-ssm232-07.txt 
INTERNET-DRAFT David Meyer INTERNET-DRAFT David Meyer
draft-ietf-mboned-ssm232-06.txt Rob Rockell draft-ietf-mboned-ssm232-07.txt Rob Rockell
Greg Shepherd Greg Shepherd
Category Best Current Practice Category Best Current Practice
Expires: March 2004 September 2003 Expires: July 2004 January 2004
Source-Specific Protocol Independent Multicast in 232/8 Source-Specific Protocol Independent Multicast in 232/8
<draft-ietf-mboned-ssm232-06.txt> <draft-ietf-mboned-ssm232-07.txt>
Status of this Document Status of this Document
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
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The key words "MUST"", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST"", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC 2119]. document are to be interpreted as described in RFC 2119 [RFC 2119].
This document is a product of the MBONED WG. Comments should be This document is a product of the MBONED WG. Comments should be
addressed to the authors, or the mailing list at addressed to the authors, or the mailing list at
mboned@ns.uoregon.edu. mboned@ns.uoregon.edu.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved. Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract Abstract
IP Multicast group addresses in the 232/8 (232.0.0.0 to IP Multicast group addresses in the 232/8 (232.0.0.0 to
232.255.255.255) range are designated as source-specific multicast 232.255.255.255) range are designated as source-specific multicast
[SSM] destination addresses and are reserved for use by source- destination addresses and are reserved for use by source-specific
specific multicast applications and protocols. This document defines multicast applications and protocols. This document defines
operational recommendations to ensure source-specific behavior within operational recommendations to ensure source-specific behavior within
the 232/8 range. the 232/8 range.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Operational practices in 232/8 . . . . . . . . . . . . . . . . 4 2. Operational practices in 232/8 . . . . . . . . . . . . . . . . 4
2.1. Preventing local sources from sending to shared tree. . . . 4 2.1. Preventing local sources from sending to shared tree. . . . 4
2.2. Preventing remote sources from being learned/joined via MSDP. 4 2.2. Preventing remote sources from being learned/joined via MSDP. 4
2.3. Preventing receivers from joining the shared tree . . . . . 5 2.3. Preventing receivers from joining the shared tree . . . . . 5
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7.2. Informative References. . . . . . . . . . . . . . . . . . . 8 7.2. Informative References. . . . . . . . . . . . . . . . . . . 8
8. Author's Addresses . . . . . . . . . . . . . . . . . . . . . . 9 8. Author's Addresses . . . . . . . . . . . . . . . . . . . . . . 9
9. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 9 9. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 9
1. Introduction 1. Introduction
Current PIM Sparse Mode (PIM-SM) [RFC2362] relies on the shared Current PIM Sparse Mode (PIM-SM) [RFC2362] relies on the shared
Rendezvous Point (RP) tree to learn about active sources for a group Rendezvous Point (RP) tree to learn about active sources for a group
and to support group-generic (not source specific) data distribution. and to support group-generic (not source specific) data distribution.
The IP Multicast group address range 232/8 has been designated for The IP Multicast group address range 232/8 has been designated for
Source-Specific PIM [SSM] applications and protocols [IANA] and Source-Specific PIM [RFC3569] applications and protocols [IANA] and
SHOULD support source-only trees only, precluding the requirement of SHOULD support source-only trees only, precluding the requirement of
an RP and a shared tree; active sources in the 232/8 range will be an RP and a shared tree; active sources in the 232/8 range will be
discovered out of band. PIM Sparse Mode Designated Routers (DR), with discovered out of band. PIM Sparse Mode Designated Routers (DR), with
local membership, are capable of joining the shortest path tree for local membership, are capable of joining the shortest path tree for
the source directly using Source-Specific PIM (also know as PIM-SSM the source directly using Source-Specific PIM (also known as PIM-SSM
or simply SSM). or simply SSM).
Operational best common practices in the 232/8 group address range Operational best common practices in the 232/8 group address range
are necessary to ensure shortest path source-only trees across are necessary to ensure shortest path source-only trees across
multiple domains in the Internet [SSM], and to prevent data from multiple domains in the Internet [RFC3569], and to prevent data from
sources sending to groups in the 232/8 range from arriving via shared sources sending to groups in the 232/8 range from arriving via shared
trees. This avoids unwanted data arrival, and allows several sources trees. This avoids unwanted data arrival, and allows several sources
to use the same group address without conflict at the receivers. to use the same group address without conflict at the receivers.
The operational practices SHOULD: The operational practices SHOULD:
o Prevent local sources from sending to shared tree o Prevent local sources from sending to shared tree
o Prevent receivers from joining the shared tree o Prevent receivers from joining the shared tree
o Prevent RP's as candidates for 232/8 o Prevent RP's as candidates for 232/8
o Prevent remote sources from being learned/joined via MSDP [MSDP] o Prevent remote sources from being learned/joined via MSDP
[RFC3618]
2. Operational practices in 232/8 2. Operational practices in 232/8
2.1. Preventing local sources from sending to shared tree 2.1. Preventing local sources from sending to shared tree
Eliminating the use of shared trees for groups in 232/8, while Eliminating the use of shared trees for groups in 232/8, while
maintaining coexistence with PIM-SM, behavior of the RP and/or the DR maintaining coexistence with PIM-SM, behavior of the RP and/or the DR
needs to be modified. This can be accomplished by needs to be modified. This can be accomplished by
- preventing data for 232/8 groups from being sent encapsulated to - preventing data for 232/8 groups from being sent encapsulated to
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Local PIM domain practices need to be enforced to prevent local Local PIM domain practices need to be enforced to prevent local
receivers from joining the shared tree for 232/8 groups. This can be receivers from joining the shared tree for 232/8 groups. This can be
accomplished by accomplished by
- preventing DR from sending (*,G) joins for 232/8 groups - preventing DR from sending (*,G) joins for 232/8 groups
- preventing RP from accepting (*,G) join for 232/8 groups - preventing RP from accepting (*,G) join for 232/8 groups
However, within a local PIM domain, any last-hop router NOT However, within a local PIM domain, any last-hop router NOT
preventing (*,G) joins may trigger unwanted (*,G) state toward preventing (*,G) joins may trigger unwanted (*,G) state toward the RP
the RP which intersects an existing (S,G) tree, allowing the which intersects an existing (S,G) tree, allowing the receiver on the
receiver on the shared tree to receive the data, breaking the shared tree to receive the data, breaking the source-specific
source-specific [SSM] service model. It is therefore recommended [RFC3569] service model. It is therefore recommended that ALL routers
that ALL routers in the domain MUST reject AND never originate in the domain MUST reject AND never originate (*,G) joins for 232/8
(*,G) joins for 232/8 groups. groups.
In those cases in which an ISP is offering its customers (or In those cases in which an ISP is offering its customers (or others)
others) the use of the ISP's RP, the ISP SHOULD NOT allow (*,G) the use of the ISP's RP, the ISP SHOULD NOT allow (*,G) joins in the
joins in the 232/8 range. 232/8 range.
2.4. Preventing RP's as candidates for 232/8 2.4. Preventing RP's as candidates for 232/8
Because PIM-SSM does not require an RP, all RPs SHOULD NOT offer Because PIM-SSM does not require an RP, all RPs SHOULD NOT offer
themselves as candidates in the 232/8 range. This can be accomplished themselves as candidates in the 232/8 range. This can be accomplished
by by
- preventing RP/BSR from announcing in the 232/8 range - preventing RP/BSR from announcing in the 232/8 range
- preventing ALL routers from accepting RP delegations in the - preventing ALL routers from accepting RP delegations in the
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6. IANA Considerations 6. IANA Considerations
This document creates no new requirements on IANA namespaces This document creates no new requirements on IANA namespaces
[RFC2434]. [RFC2434].
7. References 7. References
7.1. Normative References 7.1. Normative References
[MSDP] Meyer, D. and B. Fenner (Editors), "The Multicast
Source Discovery Protocol (MSDP)",
draft-ietf-msdp-spec-20.txt. Work in Progress.
[SSM] Holbrook, H., and B. Cain,, "Source-Specific
Multicast", draft-ietf-ssm-arch-03.txt. Work in
Progress.
[RFC2119] Bradner, S., "Key words for use in RFCs to [RFC2119] Bradner, S., "Key words for use in RFCs to
Indicate Requirement Levels", RFC 2119, March, Indicate Requirement Levels", RFC 2119, March,
1997. 1997.
[RFC2026] Bradner, S., "The Internet Standards Process -- [RFC2026] Bradner, S., "The Internet Standards Process --
Revision 3", RFC 2026/BCP 9, October, 1996. Revision 3", RFC 2026/BCP 9, October, 1996.
[RFC2028] Hovey, R. and S. Bradner, "The Organizations [RFC2028] Hovey, R. and S. Bradner, "The Organizations
Involved in the IETF Standards Process", RFC Involved in the IETF Standards Process", RFC
2028/BCP 11, October, 1996. 2028/BCP 11, October, 1996.
[RFC2362] Estrin, D., et. al., "Protocol Independent [RFC2362] Estrin, D., et. al., "Protocol Independent
Multicast-Sparse Mode (PIM-SM): Protocol Multicast-Sparse Mode (PIM-SM): Protocol
Specification", RFC 2362, June, 1998. Specification", RFC 2362, June, 1998.
[RFC2434] Narten, T., and H. Alvestrand, "Guidelines for [RFC2434] Narten, T., and H. Alvestrand, "Guidelines for
Writing an IANA Considerations Section in RFCs", Writing an IANA Considerations Section in RFCs",
RFC 2434/BCP 26, October 1998. RFC 2434/BCP 26, October 1998.
[RFC3569] Bhattacharyya, S. Editor, "An Overview of
Source-Specific Multicast (SSM)" RFC 3569, July,
2003.
[RFC3618] Meyer, D. and B. Fenner (Editors), "The Multicast
Source Discovery Protocol (MSDP)", RFC 3618,
October, 2003.
7.2. Informative References 7.2. Informative References
[IANA] http://www.iana.org [IANA] http://www.iana.org
8. Author's Addresses 8. Author's Addresses
David Meyer David Meyer
Email: dmm@1-4-5.net Email: dmm@1-4-5.net
Robert Rockell Robert Rockell
Sprint Sprint
Email: rrockell@sprint.net Email: rrockell@sprint.net
Greg Shepherd Greg Shepherd
Procket Procket
Email: shep@procket.com Email: shep@procket.com
9. Full Copyright Statement 9. Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved. Copyright (C) The Internet Society (2004). All Rights Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of Internet organizations, except as needed for the purpose of
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