Inter-Domain Routing C. Sheng Internet-Draft H. Shi, Ed. Intended status: Standards Track Huawei Expires: 26 January 2024 L. Dunbar Futurewei 25 July 2023 Corresponding Gateway Exchange in Multi-segment SD-WAN draft-sheng-idr-gw-exchange-in-sd-wan-00 Abstract The document describes the control plane enhancement for multi- segment SD-WAN to exchange the corresponding GW information between edges. 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 26 January 2024. 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. Sheng, et al. Expires 26 January 2024 [Page 1] Internet-Draft Gateway Info Exchange in SDWAN July 2023 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 3. Corresponding GW Sub-TLV . . . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . 3 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction To interconnect geographically faraway branches or SASE resources, multi-segment SD-WAN is often deployed via cloud backbone[I-D.draft-dmk-rtgwg-multisegment-sdwan]. As shown in Figure 1, CPE 1 and CPE 2 are connected to the nearest Cloud GW in different regions. For the traffic from CPE 1 to CPE 2, the CPE 1 will encapsulate the address of the egress GW(GW3) and destination CPE(CPE2) in the dataplane(see Section 5.2 of [I-D.draft-dmk-rtgwg-multisegment-sdwan]). To accomplish that, CPE needs to know their peers' corresponding GW addresses. This document proposes an control plane enhancement based on [I-D.draft-ietf-idr-sdwan-edge-discovery] to exchange the corresponding GW address between CPEs. (^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^) ( Region2 ) ( +-----+ ) ( | GW2 | ) ( +-----+ ) ( / \ ) ( / Cloud \ ) ( / Backbone \ ) ( Region1/ \Region3 ) ( +-----+ +-----+ ) ( | GW1 |---------------| GW3 | ) ( +--+--+ +--+--+ ) (^^^^|^^^^^^^^^^^^^^^^^^^^^|^^^^^) | | +--+--+ +--+--+ |CPE 1| |CPE 2| +-----+ +-----+ Figure 1: Multi-segment SD-WAN Sheng, et al. Expires 26 January 2024 [Page 2] Internet-Draft Gateway Info Exchange in SDWAN July 2023 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. Corresponding GW Sub-TLV Corresponding GW Sub-TLV within the Hybrid Underlay Tunnel UPDATE indicates the address of the corresponding GW. 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=TBD2 (C-GW subTLV) | Length (2 Octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 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, . Sheng, et al. Expires 26 January 2024 [Page 3] Internet-Draft Gateway Info Exchange in SDWAN July 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 26 January 2024 [Page 4]