Technical Summary
Data centers are critical components of the infrastructure used by
network operators to provide services to their customers. Data
centers are attached to the Internet or a backbone network by gateway
routers. One data center typically has more than one gateway for
commercial, load balancing, and resiliency reasons.
Segment Routing is a protocol mechanism that can be used within a
data center, and also for steering traffic that flows between two
data center sites. In order that one data center site may load
balance the traffic it sends to another data center site, it needs to
know the complete set of gateway routers at the remote data center,
the points of connection from those gateways to the backbone network,
and the connectivity across the backbone network.
Segment Routing may also be operated in other domains, such as access
networks. Those domains also need to be connected across backbone
networks through gateways.
This document defines a mechanism using the BGP Tunnel Encapsulation
attribute to allow each gateway router to advertise the routes to the
prefixes in the Segment Routing domains to which it provides access,
and also to advertise on behalf of each other gateway to the same
Segment Routing domain.
Working Group Summary
This draft provides a solution to allow the discovery of multiple DC gateway routers
in such scenarios. The document was developed over a period
of time in the BESS WG, but required an extended WG last call to ensure sufficient review,
as well as additional cross review of some points with the IDR WG.
Document Quality
Segment routing for supporting BGP based services between data centers is becoming
widely deployed. The document leverages relatively mature BGP extensions.
The draft received a number of comments during WG last call which were addressed.
Personnel
Document Shepherd: Matthew Bocci
Responsible Area Director: Martin Vigoureux