MPLS Working Group T. Li Internet-Draft J. Drake Intended status: Standards Track V.P. Beeram Expires: 28 April 2023 Juniper Networks T. Saad Cisco Systems I. Meilik Broadcom 25 October 2022 MPLS Network Actions for Flow-Aggregate Selector draft-li-mpls-mna-fas-00 Abstract An IETF Network Slice service provides connectivity coupled with a set of network resource commitments and is expressed in terms of one or more connectivity constructs. A Slice-Flow Aggregate refers to the set of traffic streams from one or more connectivity constructs belonging to one or more IETF Network Slices that are mapped to a set of network resources and provided the same forwarding treatment. The packets associated with a Slice-Flow Aggregate may carry a marking in the packet's network layer header to identify this association and this marking is referred to as Flow-Aggregate Selector (FAS). The FAS is used to map the packet to the associated set of network resources and provide the corresponding forwarding treatment to the packet. MPLS Network Actions (MNA) technologies are used to indicate actions for Label Switched Paths (LSPs) and/or MPLS packets and to transfer data needed for these actions. This document discusses options for using MPLS Network Actions (MNAs) to carry the FAS in MPLS packets. 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. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Li, et al. Expires 28 April 2023 [Page 1] Internet-Draft MNA FAS October 2022 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 28 April 2023. Copyright Notice Copyright (c) 2022 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 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. MPLS Network Actions . . . . . . . . . . . . . . . . . . . . 3 2.1. 12-bit Flow-Aggregate Selector (FAS12) Action . . . . . . 4 2.2. 20-bit Flow-Aggregate Selector (FAS20) Action . . . . . . 4 2.3. 20-bit Entropy/Flow-Aggregate Selector (EFAS20) Action . 5 2.4. 30-bit Entropy/Flow-Aggregate Selector (EFAS30) Action (Flags-Based) . . . . . . . . . . . . . . . . . . . . . . 5 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 3.1. 12-bit Flow-Aggregate Selector Action . . . . . . . . . . 6 3.2. 20-bit Flow-Aggregate Selector Action . . . . . . . . . . 6 3.3. 20-bit Entropy/Flow-Aggregate Selector Action . . . . . . 6 3.4. 30-bit Entropy/Flow-Aggregate Selector Action . . . . . . 7 4. Security Considerations . . . . . . . . . . . . . . . . . . . 7 5. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 6.1. Normative References . . . . . . . . . . . . . . . . . . 7 6.2. Informative References . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 Li, et al. Expires 28 April 2023 [Page 2] Internet-Draft MNA FAS October 2022 1. Introduction An IETF Network Slice [I-D.ietf-teas-ietf-network-slices] service provides connectivity coupled with a set of specific commitments of network resources between a number of endpoints over a shared underlay network. The IETF Network Slice service is expressed in terms of one or more connectivity constructs. A Network Resource Partition (NRP) [I-D.ietf-teas-ietf-network-slices] is a collection of resources identified in the underlay network to support IETF Network Slice services (or any other services that need logical network structures with required characteristics to be created). An NRP Policy [I-D.ietf-teas-ns-ip-mpls] is a policy construct that enables instantiation of mechanisms in support of service specific control and data plane behaviors on select topological elements associated with the NRP. A Slice-Flow Aggregate refers to the set of traffic streams from one or more connectivity constructs belonging to one or more IETF Network Slices that are mapped to a specific NRP and are provided the same forwarding treatment. The NRP policy dictates the identification of the flow aggregate that the packet belongs to and the corresponding forwarding treatment that needs to be applied to the packet. The packets associated with a Slice-Flow Aggregate may carry a marking in the packet's network layer header to identify this association and this marking is referred to as Flow-Aggregate Selector (FAS). [I-D.ietf-teas-ns-ip-mpls] discusses a few options for carrying the FAS in MPLS packets, including overloading the semantics of forwarding/service labels and using a dedicated identifier field. [I-D.ietf-mpls-mna-fwk] specifies an architectural framework for the MPLS Network Actions (MNA) technologies. MNA technologies are used to indicate actions for Label Switched Paths (LSPs) and/or MPLS packets and to transfer data needed for these actions. The MNA architecture can facilitate carrying the dedicated identifier based FAS in the MPLS label stack. This document discusses a few options for using MPLS network actions to carry the FAS. The proposed encodings are compliant with the MNA header encoding formats defined in [I-D.jags-mpls-mna-hdr]. The reader is expected to be familiar with terminology specified in [I-D.ietf-mpls-mna-fwk] and MNA header encoding formats defined in [I-D.jags-mpls-mna-hdr]. 2. MPLS Network Actions Li, et al. Expires 28 April 2023 [Page 3] Internet-Draft MNA FAS October 2022 2.1. 12-bit Flow-Aggregate Selector (FAS12) Action The format of the 12-bit Flow-Aggregate Selector (FAS12) Action (when encoded in the second label stack entry in the Network Action Sub- Stack): 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Opcode=TBA1 | FAS |R| 0 |S|P,H|IHS| NASL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * Name: 12-bit Flow-Aggregate Selector (FAS12) Action * Network Action Indication: The FAS12 Action indication is opcode TBA1. * Scope: The FAS12 Action is valid in all scopes. * In-Stack Data: The FAS12 Action carries 12 bits of ancillary data. The FAS is encoded in the 12 bits. The packet carrying the FAS12 action should be given the forwarding treatment specified by the associated policy. * Post-Stack Data: None. 2.2. 20-bit Flow-Aggregate Selector (FAS20) Action The format of the 20-bit Flow-Aggregate Selector (FAS20) Action: 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Opcode=TBA2 | FAS |R|NAL|S| FAS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * Name: 20-bit Flow-Aggregate Selector (FAS20) Action * Network Action Indication: The FAS20 Action indication is opcode TBA2. * Scope: The FAS20 Action is valid in all scopes. * In-Stack Data: The FAS20 Action carries 20 bits of ancillary data. The FAS is encoded in the 20 bits. The packet carrying the FAS20 action should be given the forwarding treatment specified by the associated policy. * Post-Stack Data: None. Li, et al. Expires 28 April 2023 [Page 4] Internet-Draft MNA FAS October 2022 2.3. 20-bit Entropy/Flow-Aggregate Selector (EFAS20) Action The format of the 20-bit Entropy/Flow Aggregate Selector (EFAS20) Action: 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Opcode=TBA3 | Entropy |R|NAL|S| FAS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * Name: 20-bit Entropy/Flow-Aggregate Selector (EFAS20) Action * Network Action Indication: The EFAS20 Action indication is opcode TBA3. * Scope: The EFAS20 Action is valid in all scopes. * In-Stack Data: The EFAS20 Action carries 20 bits of ancillary data. The most significant 12 bits of ancillary data is the Entropy Value. The least significant 8 bits of ancillary data is the FAS. The Entropy Value has semantics consistent with the Entropy Label [RFC6790]. While the RFC 6790 Entropy Label has some restrictions to avoid collisions with the reserved label space (0-15) [RFC3032], those restrictions are not necessary for the Entropy Value and do not apply. The packet carrying the EFAS20 action should be given the forwarding treatment specified by the associated policy. * Post-Stack Data: None. 2.4. 30-bit Entropy/Flow-Aggregate Selector (EFAS30) Action (Flags- Based) The format of the 30-bit Entropy/Flow Aggregate Selector (EFAS30) Action (when Opcode 3 is encoded in the second label stack entry in the Network Action Sub-Stack): 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Opcode=3 | Bit-Position=TBA4 |R| 1 |S|P,H|IHS| NASL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| Entropy | FAS |S| FAS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * Name: 30-bit Entropy/Flow-Aggregate Selector (EFAS30) Action * Network Action Indication: The EFAS30 Action indication is bit position TBA4. Li, et al. Expires 28 April 2023 [Page 5] Internet-Draft MNA FAS October 2022 * Scope: The EFAS30 Action is valid in all scopes. * In-Stack Data: The EFAS30 Action carries 30 bits of ancillary data. The most significant 16 bits of ancillary data is the Entropy Value. The least significant 14 bits of ancillary data is the FAS. The Entropy Value has semantics consistent with the Entropy Label [RFC6790]. While the RFC 6790 Entropy Label has some restrictions to avoid collisions with the reserved label space (0-15) [RFC3032], those restrictions are not necessary for the Entropy Value and do not apply. The packet carrying the EFAS30 action should be given the forwarding treatment specified by the associated policy. * Post-Stack Data: None. 3. IANA Considerations 3.1. 12-bit Flow-Aggregate Selector Action This document requests that IANA allocate a codepoint (TBA1) from the MPLS "HBH and Select In-Stack MPLS Network Action Indicator Opcodes" from the "IETF Review" range and the same codepoint from the MPLS "I2E In-Stack MPLS Network Action Indicator Opcodes" from the "IETF Review" range for the 12-bit Flow Aggregate Selector Action. The allocation should reference this document. 3.2. 20-bit Flow-Aggregate Selector Action This document requests that IANA allocate a codepoint (TBA2) from the MPLS "HBH and Select In-Stack MPLS Network Action Indicator Opcodes" from the "IETF Review" range and the same codepoint from the MPLS "I2E In-Stack MPLS Network Action Indicator Opcodes" from the "IETF Review" range for the 20-bit Flow Aggregate Selector Action. The allocation should reference this document. 3.3. 20-bit Entropy/Flow-Aggregate Selector Action This document requests that IANA allocate a codepoint (TBA3) from the MPLS "HBH and Select In-Stack MPLS Network Action Indicator Opcodes" from the "IETF Review" range and the same codepoint from the MPLS "I2E In-Stack MPLS Network Action Indicator Opcodes" from the "IETF Review" range for the 20-bit Entropy/Flow Aggregate Selector Action. The allocation should reference this document. Li, et al. Expires 28 April 2023 [Page 6] Internet-Draft MNA FAS October 2022 3.4. 30-bit Entropy/Flow-Aggregate Selector Action This document requests that IANA allocate a bit position (TBA4) from the MPLS "In-Stack MPLS Network Action Indicator Flags" registry for the 30-bit Entropy/Flow-Aggregate Selector Action. The allocation should reference this document. 4. Security Considerations The forwarding plane is insecure. If an adversary can affect the forwarding plane, then they can inject data, remove data, corrupt data, or modify data. MNA additionally allows an adversary to make packets perform arbitrary network actions. Link-level security mechanisms can help mitigate some on-link attacks, but does nothing to preclude hostile nodes. 5. Contributors The following individuals contributed to this document: Colby Barth Juniper Networks Email: cbarth@juniper.net Srihari R. Sangli Juniper Networks Email: ssangli@juniper.net Chandra Ramachandran Juniper Networks Email: csekar@juniper.net Kireeti Kompella Juniper Networks Email: kireeti@juniper.net 6. References 6.1. Normative References [I-D.jags-mpls-mna-hdr] Rajamanickam, J., Gandhi, R., Zigler, R., Song, H., and K. Kompella, "MPLS Network Action (MNA) Header Encodings", Work in Progress, Internet-Draft, draft-jags-mpls-mna-hdr- 02, 10 October 2022, . Li, et al. Expires 28 April 2023 [Page 7] Internet-Draft MNA FAS October 2022 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001, . [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and L. Yong, "The Use of Entropy Labels in MPLS Forwarding", RFC 6790, DOI 10.17487/RFC6790, November 2012, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 6.2. Informative References [I-D.ietf-mpls-mna-fwk] Andersson, L., Bryant, S., Bocci, M., and T. Li, "MPLS Network Actions Framework", Work in Progress, Internet- Draft, draft-ietf-mpls-mna-fwk-02, 21 October 2022, . [I-D.ietf-teas-ietf-network-slices] Farrel, A., Drake, J., Rokui, R., Homma, S., Makhijani, K., Contreras, L. M., and J. Tantsura, "Framework for IETF Network Slices", Work in Progress, Internet-Draft, draft- ietf-teas-ietf-network-slices-15, 21 October 2022, . [I-D.ietf-teas-ns-ip-mpls] Saad, T., Beeram, V. P., Dong, J., Wen, B., Ceccarelli, D., Halpern, J., Peng, S., Chen, R., Liu, X., Luis Contreras, M., Rokui, R., and L. Jalil, "Realizing Network Slices in IP/MPLS Networks", Work in Progress, Internet- Draft, draft-ietf-teas-ns-ip-mpls-00, 16 June 2022, . Authors' Addresses Li, et al. Expires 28 April 2023 [Page 8] Internet-Draft MNA FAS October 2022 Tony Li Juniper Networks Email: tony.li@tony.li John Drake Juniper Networks Email: jdrake@juniper.net Vishnu Pavan Beeram Juniper Networks Email: vbeeram@juniper.net Tarek Saad Cisco Systems Email: tsaad.net@gmail.com Israel Meilik Broadcom Email: israel.meilik@broadcom.com Li, et al. Expires 28 April 2023 [Page 9]