--- 1/draft-ietf-ospf-segment-routing-msd-20.txt 2018-09-25 15:13:07.348296659 -0700 +++ 2/draft-ietf-ospf-segment-routing-msd-21.txt 2018-09-25 15:13:07.376297341 -0700 @@ -1,23 +1,23 @@ OSPF Working Group J. Tantsura Internet-Draft Nuage Networks Intended status: Standards Track U. Chunduri -Expires: March 4, 2019 Huawei Technologies +Expires: March 29, 2019 Huawei Technologies S. Aldrin Google, Inc P. Psenak Cisco Systems - August 31, 2018 + September 25, 2018 Signaling MSD (Maximum SID Depth) using OSPF - draft-ietf-ospf-segment-routing-msd-20 + draft-ietf-ospf-segment-routing-msd-21 Abstract This document defines a way for an Open Shortest Path First (OSPF) Router to advertise multiple types of supported Maximum SID Depths (MSDs) at node and/or link granularity. Such advertisements allow entities (e.g., centralized controllers) to determine whether a particular SID stack can be supported in a given network. This document defines only one type of MSD, but defines an encoding that can support other MSD types. Here the term OSPF means both OSPFv2 @@ -31,21 +31,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on March 4, 2019. + This Internet-Draft will expire on March 29, 2019. Copyright Notice Copyright (c) 2018 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 (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -58,25 +58,25 @@ Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4 2. Node MSD Advertisement . . . . . . . . . . . . . . . . . . . 4 3. Link MSD sub-TLV . . . . . . . . . . . . . . . . . . . . . . 5 4. Using Node and Link MSD Advertisements . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . 7 - 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7 + 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 9.1. Normative References . . . . . . . . . . . . . . . . . . 8 - 9.2. Informative References . . . . . . . . . . . . . . . . . 8 + 9.2. Informative References . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 1. Introduction When Segment Routing (SR) paths are computed by a centralized controller, it is critical that the controller learns the Maximum SID Depth (MSD) that can be imposed at each node/link on a given SR path to insure that the SID stack depth of a computed path doesn't exceed the number of SIDs the node is capable of imposing. @@ -275,25 +275,45 @@ advertisement of that MSD type. However, in some cases the lack of advertisement might imply that the functionality associated with the MSD type is not supported. The correct interpretation MUST be specified when an MSD type is defined. 5. IANA Considerations This document requests IANA to allocate TLV type (TBD1) from the OSPF Router Information (RI) TLVs Registry as defined by [RFC7770]. IANA has allocated the value 12 through the early assignment process. + + Value Description Reference + ----- --------------- ------------- + 12 Node MSD This document + + Figure 3: RI Node MSD + Also, this document requests IANA to allocate a sub-TLV type (TBD2) from the OSPFv2 Extended Link TLV Sub-TLVs registry. IANA has - allocated the value 6 through the early assignment process. Finally, - this document requests IANA to allocate a sub-TLV type (TBD3) from - the OSPFv3 Extended-LSA Sub-TLV registry. + allocated the value 6 through the early assignment process. + + Value Description Reference + ----- --------------- ------------- + 6 OSPFv2 Link MSD This document + + Figure 4: OSPFv2 Link MSD + + Finally, this document requests IANA to allocate a sub-TLV type + (TBD3) from the OSPFv3 Extended-LSA Sub-TLV registry. + + Value Description Reference + ----- --------------- ------------- + TBD3 OSPFv3 Link MSD This document + + Figure 5: OSPFv3 Link MSD 6. Security Considerations Security concerns for OSPF are addressed in [RFC7474], [RFC4552] and [RFC7166]. Further security analysis for OSPF protocol is done in [RFC6863]. Security considerations, as specified by [RFC7770], [RFC7684] and [RFC8362] are applicable to this document. Implementations MUST assure that malformed TLV and Sub-TLV defined in this document are detected and do not provide a vulnerability for @@ -333,22 +354,22 @@ Mizrahi, Stephane Litkowski and Bruno Decraene for their reviews and valuable comments. 9. References 9.1. Normative References [I-D.ietf-isis-segment-routing-msd] Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg, "Signaling MSD (Maximum SID Depth) using IS-IS", draft- - ietf-isis-segment-routing-msd-13 (work in progress), July - 2018. + ietf-isis-segment-routing-msd-16 (work in progress), + September 2018. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 2015, . @@ -372,21 +393,21 @@ [I-D.ietf-idr-bgp-ls-segment-routing-msd] Tantsura, J., Chunduri, U., Mirsky, G., and S. Sivabalan, "Signaling MSD (Maximum SID Depth) using Border Gateway Protocol Link-State", draft-ietf-idr-bgp-ls-segment- routing-msd-02 (work in progress), August 2018. [I-D.ietf-ospf-mpls-elc] Xu, X., Kini, S., Sivabalan, S., Filsfils, C., and S. Litkowski, "Signaling Entropy Label Capability and Entropy Readable Label-stack Depth Using OSPF", draft-ietf-ospf- - mpls-elc-06 (work in progress), August 2018. + mpls-elc-07 (work in progress), September 2018. [I-D.ietf-pce-segment-routing] Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W., and J. Hardwick, "PCEP Extensions for Segment Routing", draft-ietf-pce-segment-routing-12 (work in progress), June 2018. [RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006, .