Inter-Domain Routing C. Sheng Internet-Draft H. Shi, Ed. Intended status: Standards Track Huawei Expires: 22 February 2024 L. Dunbar Futurewei 21 August 2023 Corresponding Gateway Exchange in Multi-segment SD-WAN draft-sheng-idr-gw-exchange-in-sd-wan-01 Abstract The document describes the control plane enhancement for multi- segment SD-WAN to exchange the corresponding GW information between edges. Discussion Venues This note is to be removed before publishing as an RFC. Discussion of this document takes place on the Inter-Domain Routing Working Group mailing list (idr@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/idr/. Source for this draft and an issue tracker can be found at https://github.com/VMatrix1900/draft-sheng-idr-gw-exchange-in-sd-wan. 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/. 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 22 February 2024. Sheng, et al. Expires 22 February 2024 [Page 1] Internet-Draft Gateway Info Exchange in SDWAN August 2023 Copyright Notice Copyright (c) 2023 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 3. Extension to SD-WAN Underlay UPDATE for Corresponding GWs . . 4 3.1. Corresponding GW Sub-TLV . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 6. Normative References . . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction [I-D.draft-dmk-rtgwg-multisegment-sdwan] describes the enterprises utilizing Cloud Providers’ backbone to interconnect their branch offices. As shown in Figure 1, CPE-1 and CPE-2 are connected to their respective Cloud Gateways (GW) in different regions. CPE-1 and CPE-2 maintain the pairwise IPsec SAs. The IPsec encrypted traffic from CPE-1 to CPE-2 is encapsulated by the GENEVE header [RFC8926], with the outer destination address being the GW1. [I-D.draft-dmk-rtgwg-multisegment-sdwan] specifies a set of sub-TLVs to carry the information of the GWs of the destination branches, e.g., GW3 for CPE-2 and other attributes. To accomplish that, CPE-1 needs to know their peers' corresponding GW addresses. This document proposes a BGP extension based on [I-D.draft-ietf-idr-sdwan-edge-discovery] for a CPE to advertise its directly connected GW address to other CPEs. Sheng, et al. Expires 22 February 2024 [Page 2] Internet-Draft Gateway Info Exchange in SDWAN August 2023 (^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^) ( Region2 ) ( +-----+ ) ( | GW2 | ) ( +-----+ ) ( / \ ) ( / Cloud \ ) ( / Backbone \ ) ( Region1/ \Region3 ) ( +-----+ +-----+ ) ( | GW1 |---------------| GW3 | ) ( +--+--+ +--+--+ ) (^^^^|^^^^^^^^^^^^^^^^^^^^^|^^^^^) | | +--+--+ +--+--+ |CPE 1| |CPE 2| +-----+ +-----+ Figure 1: Multi-segment SD-WAN 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. The following acronyms and terms are used in this document: * Cloud DC: Off-Premises Data Center, managed by 3rd party, that hosts applications, services, and workload for different organizations or tenants. * CPE: Customer (Edge) Premises Equipment. * OnPrem: On Premises data centers and branch offices. * RR Route Reflector. * SD-WAN: Software Defined Wide Area Network. In this document, “SD-WAN” refers to a policy-driven transporting of IP packets over multiple underlay networks for better WAN bandwidth management, visibility, and control. * VPN Virtual Private Network. Sheng, et al. Expires 22 February 2024 [Page 3] Internet-Draft Gateway Info Exchange in SDWAN August 2023 3. Extension to SD-WAN Underlay UPDATE for Corresponding GWs The Client Routes Update is the same as described in Section 5 of [I-D.draft-ietf-idr-sdwan-edge-discovery]. 3.1. Corresponding GW Sub-TLV The Corresponding GW Sub-TLV, within the SD-WAN-Hybrid Tunnel TLV (code point 25), carries the corresponding GW address(es) with which the SD-WAN edge is associated. The following is the structure of the Corresponding GW Sub-TLV: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=TBD | length | reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Corresponding GW Addr Family | Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (variable) + ~ ~ | Corresponding GW Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4. Security Considerations This document does not introduce any new security considerations. 5. IANA Considerations TBD. 6. Normative References [I-D.draft-dmk-rtgwg-multisegment-sdwan] Majumdar, K., Dunbar, L., Kasiviswanathan, V., and A. Ramchandra, "Multi-segment SD-WAN via Cloud DCs", Work in Progress, Internet-Draft, draft-dmk-rtgwg-multisegment- sdwan-00, 31 May 2023, . [RFC8926] Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed., "Geneve: Generic Network Virtualization Encapsulation", RFC 8926, DOI 10.17487/RFC8926, November 2020, . Sheng, et al. Expires 22 February 2024 [Page 4] Internet-Draft Gateway Info Exchange in SDWAN August 2023 [I-D.draft-ietf-idr-sdwan-edge-discovery] Dunbar, L., Hares, S., Raszuk, R., Majumdar, K., Mishra, G. S., and V. Kasiviswanathan, "BGP UPDATE for SD-WAN Edge Discovery", Work in Progress, Internet-Draft, draft-ietf- idr-sdwan-edge-discovery-10, 23 June 2023, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Authors' Addresses Cheng Sheng Huawei Beiqing Road Beijing Email: shengcheng@huawei.com Hang Shi (editor) Huawei Beiqing Road Beijing China Email: shihang9@huawei.com Linda Dunbar Futurewei Email: linda.dunbar@futurewei.com Sheng, et al. Expires 22 February 2024 [Page 5]