I run bgp.tools (with it's own route collectors, that people should totally feed :) https://bgp.tools/kb/setup-sessions ) but I feel like I can add some insight here to what I think is happening with AS147028. I've had multiple issues with networks feeding me that also are on LL-IX (https://www.peeringdb.com/ix/2343) or LL-HOST (Maybe? AS59947). It appears (based on my discussions with a few of the offending networks) that LL-IX or LL-HOST strips their own ASN (59947) from the path when you take up a transit or maybe (i'm not sure) peer on their route servers on LL-IX When you combine this and exporting to projects like RouteViews/RIPE RIS/bgp.tools, you get a peer graph that looks like the feeder ASN is peering with... almost everyone who AS59947 peers with. This has become so much of a problem (as I am slightly mad for getting this kind of data right) that bgp.tools disallows sessions to be setup if it looks like the AS either is upstreamed by AS59947 or has a port with LL-IX, (with a message to email me) The users who do email me, about 50% of them commit to adding the AS59947 ASN back on, and I enable their ability to export to bgp.tools. Hope this clears things up! This exact AS has been the cause of many frustrations for me for a while now! On Tue, Jul 12, 2022 at 11:22 PM Mike Leber via NANOG <nanog@nanog.org> wrote:
This kind of thing is a problem from time to time with the data we get from route collectors.
When we see it we have to add the culprit ASN to a filter list we keep in bgp.he.net.
It tends to be a repeat problem with some collectors and some ASNs.
We haven't really figured out why people send junk routes to route collectors.
The things we've seen aren't just route leaks. We've seen a variety of AS path spoofing.
We've already added this specific ASN to the filter list and pushed an update for bgp.he.net.
Note, this email is specifically talking about routes received from route collectors and not routes operationally received by he.net via BGP sessions with actual networks.
Mike.
On 7/12/22 12:49 PM, Eric Dugas via NANOG wrote:
A friend of mine mentioned that both our Canadian ASNs were listed in AS147028's peer list on https://bgp.he.net/AS147028 but we have no adjacency to this network.
Their peer count jumped from 1 in May 2022 to 1,800 and just a few days ago jumped to 8,800. Beside NL-IX, all the IX they are listed on are virtual IX with a few dozen "hobby networks".
The only lead I have is they use HE as transit and they're pumping back BGP feed to route collectors like RIPE RIS or Route Views with routes stripped of HE's ASN.
Eric