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Network Working Group                                        T. PusateriRequest for Comments: 4602                              Juniper NetworksCategory: Informational                                      August 2006Protocol Independent Multicast - Sparse Mode (PIM-SM)IETF Proposed Standard Requirements AnalysisStatus 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.Copyright Notice   Copyright (C) The Internet Society (2006).Abstract   This document provides supporting documentation to advance the   Protocol Independent Multicast - Sparse Mode (PIM-SM) routing   protocol from IETF Experimental status to Proposed Standard.Table of Contents1. Introduction ....................................................22.RFC 1264 Requirements ...........................................22.1. Documents Specifying the Protocol and Its Usage ............22.2. Management Information Base ................................22.3. Explicit Security Architecture .............................22.4. Implementation Existence ...................................32.4.1. XORP ................................................32.4.2. Cisco IOS/IOX .......................................32.4.3. Infosys Technologies, Ltd. ..........................32.4.4. Procket Networks ....................................32.5. Evidence of Testing ........................................42.5.1. Cisco ...............................................42.5.2. XORP ................................................42.5.3. Procket Networks ....................................52.6. Suitability ................................................52.7. Authentication Mechanisms ..................................53. Security Considerations .........................................54. Acknowledgements ................................................55. References ......................................................65.1. Normative References .......................................65.2. Informative References .....................................6Pusateri                     Informational                      [Page 1]

RFC 4602         PIM-SM Proposed Standard Req. Analysis      August 20061.  Introduction   This analysis provides supporting documentation to advance the   Protocol Independent Multicast - Sparse Mode (PIM-SM) routing   protocol from the IETF Experimental status to Proposed Standard.   PIM-SM was first published asRFC 2117 [RFC2117] in 1997 and then   again asRFC 2362 [RFC2362] in 1998.  The protocol was classified as   Experimental in both of these documents.  The PIM-SM protocol   specification was then rewritten in whole in order to more fully   specify the protocol.  It is this new specification that is to be   advanced to Proposed Standard.2.RFC 1264 RequirementsSection 4.0 of RFC 1264 [RFC1264] describes the requirements for   routing protocols to advance to Proposed Standard.  Each requirement   is listed below along with an explanation of how the requirement has   been satisfied.2.1.  Documents Specifying the Protocol and Its Usage   The authors of the new PIM-SM specification [RFC4601] have taken   considerable care to fully specify the protocol operation.  It   removes all known ambiguities and tries to normalize corner cases   that existed in the previous specification.  It has been used to   provide several interoperable implementations by developers that were   not authors of the specification.  These implementations will be   described below.2.2.  Management Information Base   A Management Information Base for PIM is currently specified inRFC2934 [RFC2934].  This MIB has many implementations and has been used   by network management applications for several years.  Updates to   this MIB to support IPv6 and other improvements based on operation   experience are in progress in the PIM Working Group of the IETF.2.3.  Explicit Security Architecture   The new PIM Sparse-Mode protocol specification contains an extensive   security section explaining its security features and limitations.   Data integrity protection and groupwise data origin authentication is   provided for PIM protocol messages.Pusateri                     Informational                      [Page 2]

RFC 4602         PIM-SM Proposed Standard Req. Analysis      August 20062.4.  Implementation Existence   There are at least 4 known independent implementations of the new   protocol specification, and there are over 6 independent   implementations of a previous version (RFC 2362) of the   specification.  The new specification was carefully written to be   backward compatible with the old specification allowing   implementations compliant withRFC 2362 to also be compliant with the   new specification.   The 4 implementations of the new version are described below.2.4.1.  XORP   The XORP project [XORP] has an open-source implementation of PIM-SM   v2 as specified inRFC 4601.  It was written by Pavlin Radoslavov   <pavlin@icir.org> and has been available to the public since December   2002.  Pavlin is not an author of the protocol specification.  It   does not use any other existing code as a base.2.4.2.  Cisco IOS/IOX   Cisco Systems, Inc., has written an implementation of the new   protocol specification that has been deployed in production routers.   There exists an IOS implementation for IPv6 only.  There exists an   IOX implementation for both IPv4 and IPv6.  This code was initially   written by Isidor Kouvelas <kouvelas@cisco.com>.  It does not depend   on any existing code base.  Isidor is a co-author of the protocol   specification.2.4.3.  Infosys Technologies, Ltd.   Infosys Technologies, Ltd. (www.infosys.com), has developed a limited   shared-tree implementation of the new Sparse-Mode specification   including PIM Hello messages, DR election, PIM join/prune messages,   join suppression, and prune override.  It was written by Bharat Joshi   <bharat_joshi@infosys.com> and is used in commercial products.   Bharat is not an author of the protocol specification.2.4.4.  Procket Networks   An implementation was written from scratch at Procket Networks by   Dino Farinacci <dino@cisco.com>.  This implementation is now owned by   Cisco Systems, Inc.  Dino is not an author of the new protocol   specification.Pusateri                     Informational                      [Page 3]

RFC 4602         PIM-SM Proposed Standard Req. Analysis      August 20062.5.  Evidence of Testing2.5.1.  Cisco   The Cisco implementation has undergone extensive laboratory testing   as well as testing in production deployments.  It is found to   interoperate with implementations of earlier versions of the PIM   Sparse-Mode protocol specification.2.5.2.  XORP   The XORP PIM-SM implementation has been thoughtfully tested   internally by the XORP project.  The emphasis during testing has been   on correctness.  In a typical setup, a PIM-SM router's behavior is   tested by connecting it to external packet generators and observers.   The packet generators are used to generate messages such as IGMP and   PIM-SM control packets, and multicast data packets.  The packet   observers are used to observe the PIM-SM control packets generated by   the PIM-SM router under test, and to observe the data packets that   may be forwarded by that router.  In addition, the router's command-   line interface has been used to observe its internal state during   some of the tests.   The test scenarios have been designed to follow the protocol   specification closely (e.g., a separate test has been created for   each event in the various protocol state machines, etc).  All test   scenarios are described in detail in the XORP PIM-SM Test Suite   [XORP-TEST].   The major tested features are:   1.  Multicast data forwarding.   2.  PIM Hello messages exchange, PIM router neighbor discovery,       option exchange, and DR election.   3.  PIM Register messages transmission and reception, PIM Register       state machine, and multicast data packets encapsulation and       decapsulation.   4.  Transmission and reception of PIM Join/Prune messages and       upstream and downstream protocol state machines.  The tests       consider the following state: (*,*,RP), (*,G), (S,G), and       (S,G,rpt).   5.  Transmission and reception of PIM Assert messages and the per-       interface (*,G) and (S,G) Assert state machines.Pusateri                     Informational                      [Page 4]

RFC 4602         PIM-SM Proposed Standard Req. Analysis      August 2006   6.  PIM Bootstrap mechanism: transmission, reception, and forwarding       of PIM Bootstrap messages (BSMs), transmission and reception of       PIM Cand-RP-Adv messages, candidate and non-candidate Bootstrap       Router (BSR) state machines, creating the RP-Set at the BSR,       receiving and using the RP-Set, and semantic fragmentation of       BSMs.   In the final tests, the tested router behaved as specified in the   PIM-SM protocol specification.  All issues found in the protocol   specification itself have been corrected in earlier versions of the   document.2.5.3.  Procket Networks   The Procket Networks implementation was deployed in many research and   service provider networks and showed interoperability with new and   old Cisco Systems implementations as well as Juniper Networks   implementations.2.6.  Suitability   PIM Sparse-Mode is a protocol for efficiently routing multicast   groups that may span wide-area (and inter-domain) Internets.  PIM   uses the underlying unicast routing to provide reverse-path   information for multicast tree building, but it is not dependent on   any particular unicast routing protocol.2.7.  Authentication Mechanisms   PIM specifies the use of the IP security (IPsec) authentication   header (AH) to provide data integrity protection and groupwise data   origin authentication of protocol messages.  The specific AH   authentication algorithm and parameters, including the choice of   authentication algorithm and the choice of key, are configured by the   network administrator.  The threats associated with receiving forged   PIM messages are outlined in the security considerations section of   the protocol specification.3.  Security Considerations   No considerations apply to a requirements analysis about a routing   protocol, only to a specification for that routing protocol.4.  Acknowledgements   Pavlin Radoslavov provided text for the section on XORP testing.   Dino Farinacci provided text for the Procket Networks testing.Pusateri                     Informational                      [Page 5]

RFC 4602         PIM-SM Proposed Standard Req. Analysis      August 20065.  References5.1.  Normative References   [RFC2934]   McCloghrie, K., Farinacci, D., Thaler, D., and B. Fenner,               "Protocol Independent Multicast MIB for IPv4",RFC 2934,               October 2000.   [RFC4601]   Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas,               "Protocol Independent Multicast - Sparse Mode (PIM-SM):               Protocol Specification (Revised)",RFC 4601, August 2006.5.2.  Informative References   [RFC1264]   Hinden, R., "Internet Engineering Task Force Internet               Routing Protocol Standardization Criteria",RFC 1264,               October 1991.   [RFC2117]   Estrin, D., Farinacci, D., Helmy, A., Thaler, D.,               Deering, S., Handley, M., Jacobson, V., Liu, C., Sharma,               P., and L. Wei, "Protocol Independent Multicast-Sparse               Mode (PIM-SM): Protocol Specification",RFC 2117, June               1997.   [RFC2362]   Estrin, D., Farinacci, D., Helmy, A., Thaler, D.,               Deering, S., Handley, M., Jacobson, V., Liu, C., Sharma,               P., and L. Wei, "Protocol Independent Multicast-Sparse               Mode (PIM-SM): Protocol Specification",RFC 2362, June               1998.   [XORP]      "XORP Project", <http://www.xorp.org>.   [XORP-TEST] "XORP PIM-SM Test Suite", <http://www.xorp.org/releases/current/docs/pim_testsuite/pim_testsuite.pdf>.Pusateri                     Informational                      [Page 6]

RFC 4602         PIM-SM Proposed Standard Req. Analysis      August 2006Author's Address   Tom Pusateri   Juniper Networks   1194 North Mathilda Avenue   Sunnyvale, CA  94089   USA   Phone: +1 408 745 2000   EMail: pusateri@juniper.netPusateri                     Informational                      [Page 7]

RFC 4602         PIM-SM Proposed Standard Req. Analysis      August 2006Full Copyright Statement   Copyright (C) The Internet Society (2006).   This document is subject to the rights, licenses and restrictions   contained inBCP 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 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 inBCP 78 andBCP 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 athttp://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.Acknowledgement   Funding for the RFC Editor function is provided by the IETF   Administrative Support Activity (IASA).Pusateri                     Informational                      [Page 8]