Partial vs Full tables

William Herrin bill at
Wed Jun 10 16:43:31 UTC 2020

On Wed, Jun 10, 2020 at 9:25 AM Robert Blayzor <rblayzor.bulk at> wrote:
> One caveat that may or may not play into this is if you use uRPF (loose)
> on your transit links.

Hi Robert,

The answer is "no," you're not running reverse-path filtering on a BGP
speaker, not even in loose mode, because that's STUPID.  At the very
best you're tying up router resources on a very large filtering table
without measurable benefit. More likely you're blackholing packets you
failed to think about, like ICMPs from routers on peering lans whose
route is intentionally not introduced to the Internet at large. I
suppose the customers don't really need pmtud or traceroute...

Bill Herrin

William Herrin
bill at

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