Re: Noisy prefixes in BGP

[Alejandro Acosta <alejandroacostaalamo () gmail com>]

Hello,

I've been following this thread, and I find it quite interesting.

I’m curious if there is an official definition for "noisy prefix" (or 
perhaps "noisy AS").



Thank you,


On 9/2/25 1:01 AM, Romain Fontugne via NANOG wrote:
> Hi,
>
> We are seeing in RIS data a constant flow of update messages from a few ASes, here is the list of the top prefixes:
>
> ┌─────────────────────┬────────────┬──────────────┐
> │       prefix        │ origin_asn │ num_announce │
> │       varchar       │  varchar   │    int64     │
> ├─────────────────────┼────────────┼──────────────┤
> │ 169.145.140.0/23    │ 6979       │       843376 │
> │ 2a03:eec0:3212::/48 │ 22616      │       435608 │
> │ 172.224.198.0/24    │ 36183      │       380117 │
> │ 172.226.208.0/24    │ 36183      │       374040 │
> │ 172.226.148.0/24    │ 36183      │       367083 │
> │ 104.206.88.0/22     │ 62904      │       316325 │
> │ 2806:202::/32       │ 28458      │       313775 │
> │ 2a03:74c0::/32      │ 203304     │       275372 │
> │ 2a02:26f7:eccc::/48 │ 36183      │       238053 │
> │ 2a02:26f7:f90c::/48 │ 36183      │       237923 │
> │ 2a02:26f7:ec8c::/48 │ 36183      │       237448 │
> │ 2a02:26f7:ee0c::/48 │ 36183      │       237287 │
> │ 2a02:26f7:f00c::/48 │ 36183      │       236646 │
> │ 2a02:26f7:ec10::/48 │ 36183      │       234305 │
> │ 2a02:26f7:c44c::/48 │ 36183      │       234204 │
> │ 2a02:26f7:d650::/48 │ 36183      │       233471 │
> │ 2a02:26f7:d258::/48 │ 36183      │       233192 │
> │ 2a02:26f7:c54c::/48 │ 36183      │       232795 │
> │ 2a02:26f7:e08c::/48 │ 36183      │       232303 │
>
> You can also see live data here:
> https://www.ihr.live/en/bgp-monitor?prefix=169.145.140.0/23&maxHops=6&rrc=rrc25.ripe.net
>
> For the first prefix this has been going on since at least last June. Anyone knows what's happening?
>
> Thanks,
> Romain Fontugne