From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc7896.txt | 283 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 283 insertions(+) create mode 100644 doc/rfc/rfc7896.txt (limited to 'doc/rfc/rfc7896.txt') diff --git a/doc/rfc/rfc7896.txt b/doc/rfc/rfc7896.txt new file mode 100644 index 0000000..1b4d53a --- /dev/null +++ b/doc/rfc/rfc7896.txt @@ -0,0 +1,283 @@ + + + + + + +Internet Engineering Task Force (IETF) D. Dhody +Request for Comments: 7896 Huawei Technologies +Updates: 5440 June 2016 +Category: Standards Track +ISSN: 2070-1721 + + + Update to the Include Route Object (IRO) Specification + in the Path Computation Element Communication Protocol (PCEP) + +Abstract + + The Path Computation Element Communication Protocol (PCEP) enables + communications between a Path Computation Client (PCC) and a PCE, or + between two PCEs. RFC 5440 defines the Include Route Object (IRO) to + specify network elements to be traversed in the computed path. The + specification does not specify if the IRO contains an ordered or + unordered list of subobjects. During recent discussions, it was + determined that there was a need to define a standard representation + to ensure interoperability. It was also noted that there is a + benefit in the handling of an attribute of the IRO's subobject, the L + bit. + + This document updates RFC 5440 regarding the IRO specification. + +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 7841. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc7896. + + + + + + + + + + + + + +Dhody Standards Track [Page 1] + +RFC 7896 IRO Specification Update June 2016 + + +Copyright Notice + + Copyright (c) 2016 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. + + This document may contain material from IETF Documents or IETF + Contributions published or made publicly available before November + 10, 2008. The person(s) controlling the copyright in some of this + material may not have granted the IETF Trust the right to allow + modifications of such material outside the IETF Standards Process. + Without obtaining an adequate license from the person(s) controlling + the copyright in such materials, this document may not be modified + outside the IETF Standards Process, and derivative works of it may + not be created outside the IETF Standards Process, except to format + it for publication as an RFC or to translate it into languages other + than English. + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2. Update in the IRO Specification . . . . . . . . . . . . . . . 3 + 2.1. Update to RFC 5440 . . . . . . . . . . . . . . . . . . . 3 + 3. Operational Considerations . . . . . . . . . . . . . . . . . 4 + 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4 + 5. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 + 5.1. Normative References . . . . . . . . . . . . . . . . . . 4 + 5.2. Informative References . . . . . . . . . . . . . . . . . 5 + Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 5 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 + + + + + + + + + + + + +Dhody Standards Track [Page 2] + +RFC 7896 IRO Specification Update June 2016 + + +1. Introduction + + The Path Computation Element Communication Protocol (PCEP) enables + communications between a Path Computation Client (PCC) and a PCE, or + between two PCEs. [RFC5440] defines the Include Route Object (IRO) + to specify network elements to be traversed in the computed path. + The specification does not specify if the IRO is an ordered or + unordered list of subobjects. In addition, it defines the L bit as + having no meaning within an IRO. + + [RFC5441] describes the use of an IRO to indicate the sequence of + domains to be traversed during inter-domain path computation. + + During recent discussions, it was determined that there was a need to + define a standard representation to ensure interoperability. + + This document updates the IRO specifications in Section 7.12 of + [RFC5440]. + +2. Update in the IRO Specification + + Section 7.12 of [RFC5440] describes the IRO as an optional object + used to specify a set of network elements to be traversed in the + computed path. It states that the L bit in the subobject has no + meaning within an IRO. It does not mention if the IRO contains an + ordered or unordered list of subobjects. + +2.1. Update to RFC 5440 + + The IRO specification is updated to remove the last line in the + Section 7.12 of [RFC5440], which states: + + "The L bit of such sub-object has no meaning within an IRO." + + Further, Section 7.12 of [RFC5440] is updated to add the following + two statements at the end of the first paragraph. + + - The content of an IRO is an ordered list of subobjects + representing a series of abstract nodes (refer to Section 4.3.2 of + [RFC3209]). + + - The L bit of an IRO subobject is set based on the loose or strict + hop property of the subobject; it is set if the subobject + represents a loose hop. If the bit is not set, the subobject + represents a strict hop. The interpretation of the L bit is as + per Section 4.3.3.1 of [RFC3209]. + + + + + +Dhody Standards Track [Page 3] + +RFC 7896 IRO Specification Update June 2016 + + +3. Operational Considerations + + Because of the lack of clarity in [RFC5440], it is possible to + encounter implementations that always interpret the IRO subobjects as + loose. When these implementations interwork with an implementation + conforming to this document, the following impact might be seen: + + o If a non-conforming (to this document) PCC sends an IRO to a + conforming (to this document) PCE, then the PCE may unexpectedly + fail to find a path (since the PCC may think of the IRO subobjects + as loose hops, but the PCE interprets them as strict hops). + + o If a conforming PCC sends an IRO containing strict hops to a non- + conforming PCE, then the PCE may erroneously return a path that + does not comply with the requested strict hops (since the PCE + interprets them all as loose hops). The PCC may check the + returned path and find the issue, or it may end up using an + incorrect path. + +4. Security Considerations + + This update in the IRO specification does not introduce any new + security considerations, apart from those mentioned in [RFC5440]. + Clarification in the supported IRO ordering or Loose hop bit handling + will not have any negative security impact. + + It is worth noting that PCEP operates over TCP. An analysis of the + security issues for routing protocols that use TCP (including PCEP) + is provided in [RFC6952]. + +5. References + +5.1. Normative References + + [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., + and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP + Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, + . + + [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation + Element (PCE) Communication Protocol (PCEP)", RFC 5440, + DOI 10.17487/RFC5440, March 2009, + . + + + + + + + + +Dhody Standards Track [Page 4] + +RFC 7896 IRO Specification Update June 2016 + + +5.2. Informative References + + [RFC5441] Vasseur, JP., Ed., Zhang, R., Bitar, N., and JL. Le Roux, + "A Backward-Recursive PCE-Based Computation (BRPC) + Procedure to Compute Shortest Constrained Inter-Domain + Traffic Engineering Label Switched Paths", RFC 5441, + DOI 10.17487/RFC5441, April 2009, + . + + [RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of + BGP, LDP, PCEP, and MSDP Issues According to the Keying + and Authentication for Routing Protocols (KARP) Design + Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013, + . + +Acknowledgments + + A special thanks to the PCE chairs for guidance regarding this work. + + Thanks to Francesco Fondelli for his suggestions in clarifying the + L bit usage. + + Thanks to Adrian Farrel for his review and comments. + + Thanks to Jonathan Hardwick for shepherding the document and + providing text in Section 3. + + Thanks to Deborah Brungard for her comments and being the responsible + AD. + + Thanks to Peter Yee for the Gen-ART review. + + Thanks to Alvaro Retana for comments during the IESG review. + +Author's Address + + Dhruv Dhody + Huawei Technologies + Divyashree Techno Park, Whitefield + Bangalore, Karnataka 560066 + India + + Email: dhruv.ietf@gmail.com + + + + + + + + +Dhody Standards Track [Page 5] + -- cgit v1.2.3