6man R. Bonica Internet-Draft Juniper Networks Intended status: Standards Track J. Halpern Expires: April 17, 2020 Ericsson Y. Kamite NTT Communications Corporation T. Niwa KDDI L. Jalil Verizon N. So F. Xu Reliance Jio G. Chen Baidu Y. Zhu G. Yang China Telecom Y. Zhou ByteDance October 15, 2019 The Per-Segment Service Instruction (PSSI) Option draft-bonica-6man-seg-end-opt-05 Abstract SRm6 encodes Per-Segment Service Instructions (PSSI) in a new IPv6 option, called the PSSI Option. This document describes the PSSI Option. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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/. 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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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 3. PSSI Identifiers . . . . . . . . . . . . . . . . . . . . . . 3 4. Option Format . . . . . . . . . . . . . . . . . . . . . . . . 3 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 8. Normative References . . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction An SRm6 [I-D.bonica-spring-srv6-plus] path provides unidirectional connectivity from its ingress node to its egress node. While an SRm6 path can follow the least cost path from ingress to egress, it can also follow any other path. An SRm6 path contains one or more segments. A segment provides unidirectional connectivity from its ingress node to its egress node. SRm6 paths are programmable. They support several instruction types, including Per-Segment Service Instructions (PSSI). The following are examples of PSSIs: o Expose a packet to a firewall policy. o Expose a packet to a sampling policy. PSSIs are executed at segment egress nodes and can be used to implement limited service chains. However, they do not provide an alternative to the Network Service Header (NSH) [RFC8300]. Bonica, et al. Expires April 17, 2020 [Page 2] Internet-Draft Per-Seg Service Instruction Opt October 2019 SRm6 encodes PSSIs in a new IPv6 option, called the PSSI Option. This document describes the PSSI Option. 2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. PSSI Identifiers PSSI Identifiers identify PSSIs. They have domain-wide significance. When a controller creates a limited service chain, also allocates a PSSI Identifier. It then distributes the following information to each node that contributes to the limited service chain: o The PSSI Identifier. o The PSSI that the node should execute when it receives a packet that has the PSSI Identifier encoded within it. 4. Option Format The PSSI Option contains the following fields: o Option Type: 8-bit selector. PSSI option. Value TBD by IANA. (Suggested value: 0x10). See Note below. o Opt Data Len - 8-bit unsigned integer. Length of the option, in octets, excluding the Option Type and Option Length fields. This field MUST be set to 4. o PSSI identifier - (32-bit selector). Identifies a PSSI. The PSSI option MAY appear in any Destination Options header, regardless of whether that Destination Options header precedes a Routing header or an upper-layer header. The PSSI option MUST NOT appear in a Hop-by-hop Options header. NOTE : The highest-order two bits of the Option Type (i.e., the "act" bits) are 00. These bits specify the action taken by a destination node that does not recognize the option. The required action is to skip over this option and continue processing the header. Bonica, et al. Expires April 17, 2020 [Page 3] Internet-Draft Per-Seg Service Instruction Opt October 2019 The third highest-order bit of the Option Type (i.e., the "chg" bit) is 0. This indicates that Option Data cannot be modified along the path between the packet's source and its destination. 5. Security Considerations The PSSI option shares many security concerns with IPv6 routing headers. In particular, any boundary filtering protecting a domain from external routing headers should also protect against external PSSI options being processed inside a domain. This occurs naturally if encapsulation is used to add routing headers to a packet. If external routing headers are allowed, then protections must also include ensuring that any provided PSSI option is properly protected, e.g. with an IPSEC AH header or other suitable means. As with Routing headers, the security assumption within a domain is that the domain is trusted to provide, and to avoid improperly modifying, the PSSI Option. 6. IANA Considerations IANA is requested to allocate a cod epoint from the Destination Options and Hop-by-hop Options registry (https://www.iana.org/assignments/ipv6-parameters/ ipv6-parameters.xhtml#ipv6-parameters-2). This option is called "PSSI". The "act" bits are 00 and the "chg" bit is 0. (Suggested value: 0x10). 7. Acknowledgements Thanks to Fred Baker, Shizhang Bi and Reji Thomas for their careful review of this document. 8. Normative References [I-D.bonica-spring-srv6-plus] Bonica, R., Hegde, S., Kamite, Y., Alston, A., Henriques, D., Halpern, J., Linkova, J., and G. Chen, "IPv6 Support for Segment Routing: SRv6+", draft-bonica-spring- srv6-plus-05 (work in progress), August 2019. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . Bonica, et al. Expires April 17, 2020 [Page 4] Internet-Draft Per-Seg Service Instruction Opt October 2019 [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", STD 89, RFC 4443, DOI 10.17487/RFC4443, March 2006, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017, . [RFC8300] Quinn, P., Ed., Elzur, U., Ed., and C. Pignataro, Ed., "Network Service Header (NSH)", RFC 8300, DOI 10.17487/RFC8300, January 2018, . Authors' Addresses Ron Bonica Juniper Networks 2251 Corporate Park Drive Herndon, Virginia 20171 USA Email: rbonica@juniper.net Joel Halpern Ericsson P. O. Box 6049 Leesburg, Virginia 20178 USA Email: joel.halpern@ericsson.com Yuji Kamite NTT Communications Corporation 3-4-1 Shibaura, Minato-ku Tokyo 108-8118 Japan Email: y.kamite@ntt.com Bonica, et al. Expires April 17, 2020 [Page 5] Internet-Draft Per-Seg Service Instruction Opt October 2019 Tomonobu Niwa KDDI 3-22-7, Yoyogi, Shibuya-ku Tokyo 151-0053 JP Email: to-niwa@kddi.com Luay Jalil Verizon Richardson, Texas USA Email: luay.jalil@one.verizon.com Ning So Reliance Jio 3010 Gaylord PKWY, Suite 150 Frisco, Texas 75034 USA Email: Ning.So@ril.com Fengman Xu Reliance Jio 3010 Gaylord PKWY, Suite 150 Frisco, Texas 75034 USA Email: Fengman.Xu@ril.com Gang Chen Baidu No.10 Xibeiwang East Road Haidian District Beijing 100193 P.R. China Email: phdgang@gmail.com Bonica, et al. Expires April 17, 2020 [Page 6] Internet-Draft Per-Seg Service Instruction Opt October 2019 Yongqing Zhu China Telecom 109 West Zhongshan Ave, Tianhe District Guangzhou P.R. China Email: zhuyq.gd@chinatelecom.cn Guangming Yang China Telecom 109 West Zhongshan Ave, Tianhe District Guangzhou P.R. China Email: yanggm.gd@chinatelecom.cn Yifeng Zhou ByteDance Building 1, AVIC Plaza, 43 N 3rd Ring W Rd Haidian District Beijing 100000 P.R. China Email: yifeng.zhou@bytedance.com Bonica, et al. Expires April 17, 2020 [Page 7]