Re: Longest prepend( 255 times) as path found

[Chriztoffer <ch () ntrv dk>]

On Thu, 25 Aug 2022, 16:31 Alistair Mackenzie, <magicsata () gmail com> wrote:

> There are some generally accepted and useful filters found at
> https://bgpfilterguide.nlnog.net/. There is one which covers excess
> prepends.


It's generally accepted to filter **very** long as paths.

As Alistair pointed to. The guide mentions 100x max path length as a
(current!) value that won't filter out long current as paths. (And protect
you from others missing filtering.)
https://bgpfilterguide.nlnog.net/guides/long_paths/

If you want to go for a lower than 100 value. RIB dumps from the ripe ris
collectors / route-views may be the most accessible starting point for data
to analyse.

If you want to read data about avg as path lengths over the years. APNIC
publishes data about it.
https://blog.apnic.net/2022/01/06/bgp-in-2021-the-bgp-table/