Hi Suresh,

Could be all of what you suggest... I've really not had the time to go delving into these (plus it would need the willing cooperation of the AS in question, which might have happened 25 years ago when some of us were chasing down meaningless deaggregation). These massive only affect certain paths and, in RouteViews case, certain peers in certain locations (some locations they send us vast numbers of updates, others they are perfectly normal). I could speculate infrastructure issues, or internal routers failing to converge, or BGP attribute changes, or a script gone mad, or broken BGP implementations,... Not sure if it is those automatic load balancers tbh, they don't show the vast level of updates, but just generate a steady background noise (you can see the obvious candidates in Geoff's BGP Update Report).

philip
--

Suresh Ramasubramanian wrote on 10/2/2025 12:16:
Philip, I’ve kept meaning to ask you for decades but did you ever find the root cause  of all this noise- is this due to a bug in some version of a router OS or is this being caused by a malfunctioning script at the provider that triggers BGP updates?

From: NANOG <nanog-bounces+ops.lists=gmail.com@nanog.org> on behalf of Philip Smith <pfs@routeviews.org>
Date: Monday, 10 February 2025 at 6:32 AM
To: James Bensley <lists+nanog@bensley.me>
Cc: NANOG <nanog@nanog.org>
Subject: Re: Noisy prefixes in BGP

I guess all we can do is keep highlighting the problem (I highlight
Geoff's BGP Update report almost every BGP Best Practice training I run
here in AsiaPac, for example) - but how to make noisy peers go away,
longer term...? :-(

> * These problems aren’t DFZ wide. Peer A might be sending a bajillion updates to peer B, but peer B sees there is no change in the route and correctly doesn’t forward the update onwards to it’s peers / public collectors. So this is probably happing a lot more than we see via RIS or RouteViews. Only some parts of the DFZ will be receiving the gratuitous updates/withdraws.