Hi. > 2. p3619 : "Then each new prefix will be propagated in parallel." > > Not really. Even if you assume the AS A sent a single UPDATE with 1 NLRI for > each prefix, ASes B C D are going to aggregate multiple NLRI changes in a > single UPDATE message to each other. This isn't going to cause the > amplification claimed.
Perhaps the authors meant that each UPDATE message sent by AS A has unique path attributes and thus ensuring that ASes B, C and D can not aggregate multiple NLRIs into a single UPDATE message. I tried to replicate the "BGP Vortices Delay Network Convergence" test demonstrated in paragraph 5.3. Setup(drawing: https://gist.github.com/tonusoo/1cced39aa6ae53143d12623a05f02331) is very similar to figure 4b on the page 3621, but all my routers are running BIRD 3(single thread mode). Router "rY"(ingress) injects real BGP feed into the lab setup, router "rX"(upstream) periodically advertises and withdraws 50 routes and router "rK" injects 5k prefixes for the BGP vortex. Running the packet capture on Linux bridge connecting, for example, the "rN" and "rM" routers confirms that the BGP vortex is ongoing and I'm seeing well over 10k UPDATE messages per second. However, I might be doing something wrong, but I don't see the delays shown on figure 5a on page 3622. That is, 50 routes advertised or withdrawn by "rX" are propagated to "rZ" within few hundred milliseconds and not delayed for 10+ seconds. Martin _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/QHFLJAWBL7HULUJOO77PVLXKRTYR5SQR/
