Network Working Group P. Quinn Internet-Draft Cisco Systems, Inc. Intended status: Standards Track U. Elzur Expires: August 2, 2018 Intel S. Majee F5 January 29, 2018 Network Service Header TLVs draft-ietf-sfc-nsh-tlv-00.txt Abstract This draft describes Network Service Header (NSH) MD-Type 2 metadata TLVs that can be used within a service function path. 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 http://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 August 2, 2018. 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 (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. Quinn, et al. Expires August 2, 2018 [Page 1] Internet-Draft Network Service Header TLVs January 2018 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. NSH Type 2 Format . . . . . . . . . . . . . . . . . . . . . . 2 3. NSH Type 2 TLVs . . . . . . . . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . 7 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1. Normative References . . . . . . . . . . . . . . . . . . 7 7.2. Informative References . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction Network Service Header [NSH] is the SFC encapsulation protocol used to create Service Function Chains. As such, NSH provides two key elements: 1. Service Function Path identification 2. Metadata NSH further defines two metadata formats (MD Types): 1 and 2. MD Type 1 defines fixed length, 16 byte metadata, whereas MD Type 2 defines a variable-length TLV format for metadata. This draft defines some common TLVs for use with NSH MD Type 2. This draft does not address metadata usage, updating/chaining of metadata or other SFP functions. Those topics are described in NSH. 2. NSH Type 2 Format A NSH is composed of a 4-byte Base Header, a 4-byte Service Path Header and Context Headers. The Base Header identifies the MD-Type in use: 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ver|O|C|R|R|R|R|R|R| Length | MD Type | Next Protocol | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: NSH Base Header Please refer to NSH [NSH] for a detailed header description. Quinn, et al. Expires August 2, 2018 [Page 2] Internet-Draft Network Service Header TLVs January 2018 When the base header specifies MD Type= 0x2, zero or more Variable Length Context Headers MAY be added, immediately following the Service Path Header. Therefore, Length = 0x2, indicates that only the Base Header followed by the Service Path Header are present. The number, indicated in the length field, of optional Variable Length Context Headers MUST be of an integer indicating length in 4-bytes words Figure 3 below depicts the format the context header. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class |C| Type |R|R|R| Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Variable Metadata | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: NSH TLV Format 3. NSH Type 2 TLVs As per NSH, TLV Class 0-7 are reserved for standards use. In this draft we use TLV Class 0 for the following Types: +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type |R|R|R| Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Variable Metadata | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: NSH TLV Class=0x0 1. Forwarding Context This TLV carries network-centric forwarding context, used for segregation and forwarding scope. Forwarding context can take several forms depending on the network environment. Commonly used data includes VXLAN/VXLAN- GPE VNID, VRF identification or VLAN. Quinn, et al. Expires August 2, 2018 [Page 3] Internet-Draft Network Service Header TLVs January 2018 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type=0x1 |R|R|R| L=0x2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |CT (4)| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tentant ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Context Type (CT), 4 bits: 0x0: 24 bit VXLAN/LISP virtual network identifier (VNI) 0x1: 32 bit MPLS VPN label 0x2: VLAN Figure 4: Forwarding Context 2. Tenant Tenant identification is often used for segregation within a multi-tenant environment. Orchestration system generated tenant IDs are an example of such data. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type=0x4 |R|R|R| L=0x3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |TT (4)| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tenant ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tenant ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Tenant Type (TT), 4 bits: 0x0: 32 bit 0x1: 64 bit Figure 5: Tenant Identifier 3. Content Type Provides explicit information about the content being carried, for example, type of video or content value for billing purposes Quinn, et al. Expires August 2, 2018 [Page 4] Internet-Draft Network Service Header TLVs January 2018 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type=0x6 |R|R|R| L=0x1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Content Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: Content Type 4. Ingress Network Information This data identifies ingress network node, and, if required, ingress interface. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type=0x7 |R|R|R| L=0x2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Interface/Port | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: Ingress Network Info 5. Flow ID Flow ID provides a representation of flow. Akin, but not identical to the usage described in [RFC6437] +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type=0x8 |R|R|R| L=0x1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flow ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8: Flow ID 6. Source and/or Destination Groups Intent-based systems can use this data to express the logical grouping of source and/or destination objects. [GROUPBASEDPOLICY] and [GROUPPOLICY] provide examples of such a system. Quinn, et al. Expires August 2, 2018 [Page 5] Internet-Draft Network Service Header TLVs January 2018 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type=0x9 |R|R|R| L=0x3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |GT(4) | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Group | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Dest Group | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Group type (4): 0x1: Group Based Policy (GBP) end point group (EPG) Figure 9: End Point Group 7. Universal Resource Identifier (URI) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type=0xA |R|R|R| L=var | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |UT(4) | URI | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ URI ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ URI type (4): 0x1: URI in standard string format as defined in RFC 3986 0x2: URI represented in a compacted hash format Figure 10: URI 8. Policy Identifier (POLICY_ID) Policy is often referred by a system generated identifier which is then used by the devices to lookup the content of the policy locally. For example this identifier could be an index to an array, a lookup key, a database Id. The identifier allows enforcement agents or services to lookup up the content of their part of the policy quite efficiently. Quinn, et al. Expires August 2, 2018 [Page 6] Internet-Draft Network Service Header TLVs January 2018 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV Class = 0x0 |C| Type=0xB |R|R|R| L=0x2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | POLICY_ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ POLICY_ID ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 11: POLICY_ID 4. Security Considerations NSH describes the requisite security considerations for protecting NSH metadata. 5. Acknowledgments The authors would like to thank Behcet Sarikaya, Dirk von Hugo and Mohamed Boucadair for their work regarding usage of subscriber and host information TLVs. 6. IANA Considerations IANA is requested to create a new "Network Service Header (NSH) TLV Type" registry. TLV types 0-127 are specified in this document. New values are assigned via Standards Action [RFC5226]. 7. References 7.1. Normative References [NSH] Quinn, P., Ed. and U. Elzur, Ed., "Network Service Header", 2016, . 7.2. Informative References [GROUPBASEDPOLICY] OpenStack, "Group Based Policy", 2014, . [GROUPPOLICY] OpenDaylight, "Group Policy", 2014, . Quinn, et al. Expires August 2, 2018 [Page 7] Internet-Draft Network Service Header TLVs January 2018 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", RFC 5226, DOI 10.17487/RFC5226, May 2008, . [RFC6437] Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme, "IPv6 Flow Label Specification", RFC 6437, DOI 10.17487/RFC6437, November 2011, . Authors' Addresses Paul Quinn Cisco Systems, Inc. Email: paulq@cisco.com Uri Elzur Intel Email: uri.elzur@intel.com Sumandra Majee F5 Email: S.Majee@F5.com Quinn, et al. Expires August 2, 2018 [Page 8]