Selectively Sharing Multipath Routes in BGP

Note: Presentation times are in Pacific Daylight Time (PDT).

Thursday, June 03, 2021 - 8:45 am9:15 am

Trisha Biswas, Fastly, Inc.


Border Gateway Protocol (BGP) is the most widely used network protocol to distribute routing information between network service providers. Traditionally, BGP speakers propagate only the best path to a given address prefix over a session. This achieves better scaling at the cost of path diversity. BGP add-paths (RFC7911) allows sharing of multiple paths for the same prefix, helping achieve faster re-convergence. In today's networks, simply enabling add-paths however, could result in sharing millions of routes with a peer, potentially overwhelming it.

Selective advertisement of multiple paths allows a BGP speaker to pick additional paths to share, based on other route attributes. This extension, currently an IETF draft, helps unlock the potential of purposefully sending additional routes, as opposed to bombarding the peer with millions of extra routes. In this talk, we will present a use-case for the application of selective add-paths, along with a working demonstration of the feature.

Trisha Biswas, Fastly, Inc.

Trisha is a networking researcher with several years of experience in cloud network infrastructure and routing design. She works as a senior software engineer at Fastly, Inc., a company that provides an edge cloud platform for faster content delivery. Her current work involves design of the network control plane in edge cloud networks, where routing decisions are made to optimize traffic flow. She obtained her Ph.D. from North Carolina State University, focusing on resilient routing protocols for wireless ad hoc networks. In her spare time, she likes to travel, hike, backpack and sing.

@conference {272729,
author = {Trisha Biswas},
title = {Selectively Sharing Multipath Routes in {BGP}},
year = {2021},
publisher = {{USENIX} Association},
month = jun,