Internet-Draft Gateway Info Exchange in SDWAN August 2023
Sheng, et al. Expires 22 February 2024 [Page]
Workgroup:
Inter-Domain Routing
Internet-Draft:
draft-sheng-idr-gw-exchange-in-sd-wan-01
Published:
Intended Status:
Standards Track
Expires:
Authors:
C. Sheng
Huawei
H. Shi, Ed.
Huawei
L. Dunbar
Futurewei

Corresponding Gateway Exchange in Multi-segment SD-WAN

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.

Table of Contents

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.

  (^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^)
  (            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:

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, , <https://datatracker.ietf.org/doc/html/draft-dmk-rtgwg-multisegment-sdwan-00>.
[RFC8926]
Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed., "Geneve: Generic Network Virtualization Encapsulation", RFC 8926, DOI 10.17487/RFC8926, , <https://www.rfc-editor.org/rfc/rfc8926>.
[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, , <https://datatracker.ietf.org/doc/html/draft-ietf-idr-sdwan-edge-discovery-10>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/rfc/rfc8174>.

Authors' Addresses

Cheng Sheng
Huawei
Beiqing Road
Beijing
Hang Shi (editor)
Huawei
Beiqing Road
Beijing
China
Linda Dunbar
Futurewei