Internet DRAFT - draft-sheng-idr-gw-exchange-in-sd-wan
draft-sheng-idr-gw-exchange-in-sd-wan
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.
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This Internet-Draft will expire on 1 September 2024.
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Copyright Notice
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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 .
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(^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^)
( 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.
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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.
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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
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[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,
<https://datatracker.ietf.org/doc/html/draft-dmk-rtgwg-
multisegment-sdwan-07>.
[RFC8926] Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed.,
"Geneve: Generic Network Virtualization Encapsulation",
RFC 8926, DOI 10.17487/RFC8926, November 2020,
<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-12, 23 June 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-
sdwan-edge-discovery-12>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<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,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
Authors' Addresses
Cheng Sheng
Huawei
Beiqing Road
Beijing
Email: shengcheng@huawei.com
Hang Shi (editor)
Huawei
Beiqing Road
Beijing
China
Email: shihang9@huawei.com
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Linda Dunbar
Futurewei
Email: linda.dunbar@futurewei.com
Gyan Mishra
Verizon
Email: gyan.s.mishra@verizon.com
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