| Internet-Draft | Gateway Info Exchange in SDWAN | August 2023 |
| Sheng, et al. | Expires 22 February 2024 | [Page] |
The document describes the control plane enhancement for multi-segment SD-WAN to exchange the corresponding GW information between edges.¶
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 ([email protected]), 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.¶
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[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|
+-----+ +-----+
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:¶
The Client Routes Update is the same as described in Section 5 of [I-D.draft-ietf-idr-sdwan-edge-discovery].¶
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
¶
This document does not introduce any new security considerations.¶
TBD.¶