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diff --git a/doc/rfc/rfc5186.txt b/doc/rfc/rfc5186.txt new file mode 100644 index 0000000..e6b610e --- /dev/null +++ b/doc/rfc/rfc5186.txt @@ -0,0 +1,339 @@ + + + + + + +Network Working Group B. Haberman +Request for Comments: 5186 Johns Hopkins University +Category: Informational J. Martin + Woven Systems + May 2008 + + + Internet Group Management Protocol Version 3 (IGMPv3) / + Multicast Listener Discovery Version 2 (MLDv2) and + Multicast Routing Protocol Interaction + +Status of This Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Abstract + + The definitions of the Internet Group Management Protocol Version 3 + (IGMPv3) and Multicast Listener Discovery Version 2 (MLDv2) require + new behavior within the multicast routing protocols. The additional + source information contained in IGMPv3 and MLDv2 messages + necessitates that multicast routing protocols manage and utilize the + information. This document describes how multicast routing protocols + will interact with these source-filtering group management protocols. + +1. Introduction + + The definitions of IGMPv3 [IGMP3] and MLDv2 [MLDv2] require new + behavior within the multicast routing protocols. The additional + source information contained in IGMPv3 and MLDv2 messages + necessitates that multicast routing protocols manage and utilize the + information. This document will describe how multicast routing + protocols will interpret information learned from these source- + filtering group management protocols. + +2. Multicast Forwarding State + + Existing multicast routing protocols utilize the group management + database in determining if local members exist for a particular + multicast group. With previous group management protocols, this + database had one type of record indicating the group for which there + was interest and the associated local interfaces. + + + + + + + +Haberman & Martin Informational [Page 1] + +RFC 5186 IGMPv3/MLDv2 and Multicast Protocols May 2008 + + + In the case of IGMPv3 and MLDv2, these routing protocols may now + build multicast forwarding state based on the source filter + information available for each multicast group that has local + membership. This requires that the group management database have + four record types. Only one record may exist for a given interface + and a given multicast group. + + 1. EXCLUDE <> + The EXCLUDE <> record indicates interest in all sources + destined to this group address for a set of local interfaces. + It is equivalent to the single record type existing in previous + versions of the group management protocols. + + 2. INCLUDE <> + The INCLUDE <> record indicates that there is no interest in + any sources destined to this group address for a set of local + interfaces. + + 3. EXCLUDE <list> + The EXCLUDE <list> record indicates that there is interest in + all sources other than the specifically listed sources for a + set of local interfaces. + + 4. INCLUDE <list> + The INCLUDE <list> record indicates that there is interest in + only the specifically listed sources for a set of local + interfaces. + + The records in the group management database should be utilized when + generating forwarding state for a multicast group. If the source + address in the multicast packet exists in the database for the + specified multicast group and is in an INCLUDE list or is not listed + in an EXCLUDE list, the multicast routing protocol should add the + interface to the list of downstream interfaces; otherwise, it should + not be added based on local group membership. + +3. DVMRP Interaction + + The Distance Vector Multicast Routing Protocol (DVMRP) [DVMRP] does + not incorporate any knowledge of the multicast group's senders. + Therefore, DVMRP will act only on the multicast group address + contained in an IGMPv3 or MLDv2 report. + + Future standardized versions of DVMRP may incorporate pruning and + grafting messages similar to PIM-DM (discussed in Section 5). The + rules defined in Section 5 can be applied in this situation. + + + + + +Haberman & Martin Informational [Page 2] + +RFC 5186 IGMPv3/MLDv2 and Multicast Protocols May 2008 + + +4. MOSPF Interaction + + In Multicast Extensions to OSPF (MOSPF) [MOSPF], the consideration of + source filter information in the group management database is limited + to the building of forwarding state (discussed above). This is due + to the flooding of group-membership-LSAs within MOSPF. + +5. PIM-DM Interaction + + The PIM-DM protocol [PIMDM] interaction with a source-filtering group + management protocol is important in two areas: multicast distribution + tree pruning and multicast distribution tree grafting. The following + sections will describe the behavior needed in PIM-DM to interoperate + with IGMPv3 and MLDv2. + +5.1. PIM-DM Prunes + + PIM-DM prune messages are initiated when a PIM-DM router determines + that there are no entities interested in the data flowing on the + (S,G) forwarding state. If the multicast router is running IGMPv3 or + MLDv2, this is determined by the source S being in EXCLUDE state in + the source filter for the destination G, or all interest in G being + terminated for an existing (S,G) forwarding entry. + +5.2. PIM-DM Grafts + + PIM-DM graft messages are sent in order to override an existing PIM- + DM prune. In the case of IGMPv3 or MLDv2, this occurs when prune + state exists for (S,G) and a state change occurs in which the source + filter state for S changes to INCLUDE for the specified G. + +6. PIM-SM Interaction + + A PIM-SM interaction takes place when a PM-SM [PIMSM] router receives + an IGMP or MLD message regarding a group address that is in the Any + Source Multicast (ASM) range. This range is defined as the entire + multicast address space excluding the global SSM range [SSM] and any + locally defined Source Specific space. + + + + + + + + + + + + + +Haberman & Martin Informational [Page 3] + +RFC 5186 IGMPv3/MLDv2 and Multicast Protocols May 2008 + + +6.1. PIM-SM Joins (ASM Behavior) + + PIM-SM join messages are initiated when a PIM-SM router determines + that there are entities interested in a specific group or a specific + source sending to the group. If this is due to an IGMPv3 or MLDv2 + report with a zero-length EXCLUDE list, then the join is sent as a + (*,G) join towards the RP. + + If the join is triggered by an IGMPv3 or MLDv2 state change that + affects source information, the PIM-SM join is sent as a (S,G) join + towards the specific source. This behavior optimizes the join + process, as well as facilitates the adoption of the SSM model. The + generation of this (S,G) join can cause failures in architectures + where leaf routers do not have global reachability, and thus, can be + overridden by local policy. If this is the case, then all triggered + joins are sent towards the RP as (*,G) joins. The router sending the + (*,G) join is responsible for filtering the data as per the IGMPv3 + database before forwarding. + +6.2. PIM-SM Prunes (ASM Behavior) + + PIM-SM prune messages are initiated when a PIM-SM router determines + that there are no entities interested in a specific group, or a + specific source sending to the group. If this is triggered by either + receiving a report with an EXCLUDE or if a specific Source/Group + times out, then an (S,G) prune is sent towards the upstream router. + If all of the IGMPv3 or MLDv2 derived requests for a group time out, + then (S,G) and (*,G) prunes are sent upstream as needed to stop all + flow of traffic for that group. + +7. PIM-SSM Interaction + + A PIM-SSM interaction takes place when a PIM-SM router receives an + IGMPv3 or MLDv2 message regarding a group address that is in the + Source Specific Multicast range. This behavior is not defined in + this document, but rather in [PIMSM]. + +8. Security Considerations + + This document does not introduce any additional security issues above + and beyond those already discussed in [PIMDM], [PIMSM], [IGMP3], and + [MLDv2]. + +9. Acknowledgements + + The authors would like to thank Murali Brahmadesam, Leonard Giuliano, + and Hal Sandick for their feedback and suggestions. + + + + +Haberman & Martin Informational [Page 4] + +RFC 5186 IGMPv3/MLDv2 and Multicast Protocols May 2008 + + +10. Normative References + + [IGMP3] Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A. + Thyagarajan, "Internet Group Management Protocol, Version 3", + RFC 3376, October 2002. + + [MLDv2] Vida, R., Ed., and L. Costa, Ed., "Multicast Listener + Discovery Version 2 (MLDv2) for IPv6", RFC 3810, June 2004. + + [DVMRP] Waitzman, D., Partridge, C., and S. Deering, "Distance Vector + Multicast Routing Protocol", RFC 1075, November 1988. + + [MOSPF] Moy, J., "Multicast Extensions to OSPF", RFC 1584, March + 1994. + + [PIMDM] Adams, A., Nicholas, J., and W. Siadak, "Protocol Independent + Multicast - Dense Mode (PIM-DM): Protocol Specification + (Revised)", RFC 3973, January 2005. + + [PIMSM] Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas, + "Protocol Independent Multicast - Sparse Mode (PIM-SM): + Protocol Specification (Revised)", RFC 4601, August 2006. + + [SSM] Holbrook, H. and B. Cain, "Source-Specific Multicast for IP", + RFC 4607, August 2006. + +Authors' Addresses + + Brian Haberman + The Johns Hopkins University Applied Physics Laboratory + 11100 Johns Hopkins Road + Laurel, MD 20723-6099 + US + + Phone: +1 443 778 1319 + EMail: brian@innovationslab.net + + Jim Martin + Woven Systems + 2455 Augustine Drive, Suite 211 + Santa Clara, CA 95054 + US + + Phone: +1 408 654-8143 + EMail: jim@wovensystems.com + + + + + + +Haberman & Martin Informational [Page 5] + +RFC 5186 IGMPv3/MLDv2 and Multicast Protocols May 2008 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2008). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND + THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF + THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; nor does it represent that it has + made any independent effort to identify any such rights. Information + on the procedures with respect to rights in RFC documents can be + found in BCP 78 and BCP 79. + + Copies of IPR disclosures made to the IETF Secretariat and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF on-line IPR repository at + http://www.ietf.org/ipr. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + + + + + + + + + + + + +Haberman & Martin Informational [Page 6] + |