Inter-Domain Routing C. Sheng Internet-Draft H. Shi, Ed. Intended status: Standards Track Huawei Expires: 1 September 2024 L. Dunbar Futurewei G. Mishra Verizon 29 February 2024 Associated Gateway Exchange in Multi-segment SD-WAN draft-sheng-idr-gw-exchange-in-sd-wan-02 Abstract The document describes the control plane enhancement for multi- segment SD-WAN to exchange the associated 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 1 September 2024. Sheng, et al. Expires 1 September 2024 [Page 1] Internet-Draft Gateway Info Exchange in SDWAN February 2024 Copyright Notice Copyright (c) 2024 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 Associated GWs . . . 4 3.1. NLRI SD-WAN SAFI Route Type For GW . . . . . . . . . . . 4 3.2. Associated GW Sub-TLV . . . . . . . . . . . . . . . . . . 5 4. Manageability Considerations . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 7. Normative References . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction [I-D.draft-dmk-rtgwg-multisegment-sdwan] describes how enterprises leverage Cloud Providers’ backbone infrastructure to interconnect their branch offices. As illustrated in Figure 1, CPE-1 and CPE-2 establish connections to their respective Cloud Gateways (GW) in distinct regions. CPE-1 and CPE-2 maintain the pairwise IPsec Security Associations (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 convey information about the GWs associated with the destination branches, such as GW3 for CPE-2, along with additional attributes. To accomplish this, CPE-1 must be aware of the associated GW addresses of their peers. This document proposes a BGP extension, building upon [I-D.draft-ietf-idr-sdwan-edge-discovery], enabling a CPE to advertise its directly connected GW address to other CPEs . Sheng, et al. Expires 1 September 2024 [Page 2] Internet-Draft Gateway Info Exchange in SDWAN February 2024 (^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^) ( 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 1 September 2024 [Page 3] Internet-Draft Gateway Info Exchange in SDWAN February 2024 3. Extension to SD-WAN Underlay UPDATE for Associated GWs The Client Routes Update is the same as described in Section 5 of [I-D.draft-ietf-idr-sdwan-edge-discovery]. 3.1. NLRI SD-WAN SAFI Route Type For GW Adding a new attribute (Associated-Gateway Sub-TLV) to the SD-WAN- Hybrid Tunnel Encoding which is included in the SD-WAN SAFI (=74) Underlay Tunnel Update: +------------------+ | Route Type | 2 octet +------------------+ | Length | 2 Octet +------------------+ | Type Specific | ~ Value (Variable) ~ | | +------------------+ NLRI Route-Type = 2: For advertising the detailed properties of the transit gateways for the edge. The SD-WAN NLRI Route-Type =2 has the following encoding: +------------------+ | Route Type = 2 | 2 octet +------------------+ | Length | 2 Octet +------------------+ | SD-WAN Color | 4 octets +------------------+ | SD-WAN-Node-ID | 4 or 16 octets +------------------+ SD-WAN-Color: To represent a group of tunnels that correlate with the Color-Extended-community included in a client route UPDATE. When multiple SD-WAN edges can reach a client route co-located at one site, the SD-WAN- Color can represent a group of tunnels terminated at those SD-WAN edges co-located at the site, which effectively represents the site. SD-WAN Node ID: The node's IPv4 or IPv6 address. Sheng, et al. Expires 1 September 2024 [Page 4] Internet-Draft Gateway Info Exchange in SDWAN February 2024 3.2. Associated GW Sub-TLV The Associated GW Sub-TLV, within the SD-WAN-Hybrid Tunnel TLV (code point 25), carries the associated GW address(es) with which the SD- WAN edge is associated. The following is the structure of the associated 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 | Priority | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Associated GW Addr Family | Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (variable) + ~ ~ | Associated GW Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Priority (1-255) indicate the preference of the GW. The higher the value, the more preference is the GW. Priority = 0 represents that the connection exists but request Cloud Backbone not to choose the GW if possible. 4. Manageability Considerations Effective management of SD-WAN edge nodes and the exchange of associated cloud gateway information are critical aspects in ensuring a robust and scalable SD-WAN deployment. 5. Security Considerations This document does not introduce any new security considerations. 6. IANA Considerations Need IANA to assign a new Sub-TLV Type under the SD-WAN-Hybrid Tunnel TLV. - SD-WAN Associated GW Sub-TLV. 7. Normative References Sheng, et al. Expires 1 September 2024 [Page 5] Internet-Draft Gateway Info Exchange in SDWAN February 2024 [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-07, 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, . [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-12, 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 Sheng, et al. Expires 1 September 2024 [Page 6] Internet-Draft Gateway Info Exchange in SDWAN February 2024 Linda Dunbar Futurewei Email: linda.dunbar@futurewei.com Gyan Mishra Verizon Email: gyan.s.mishra@verizon.com Sheng, et al. Expires 1 September 2024 [Page 7]