On Tue, Oct 08, 2024 at 04:46:07PM +0200, Alexander Zubkov via Bird-users wrote:
Hi Radoslaw,
Do I get it right, that you have 2 bgp peerings here. First your route passes this peering: AS8075 <-> AS20940 then it passes other peering: AS4290006033 <-> AS4290006002
Then it is an expected behaviour. Because the ASN is prepended when route is exported over eBGP session. And the local ASN is prepended. So you see that when you receive the route over the first peering, it is prepended with AS8075. Then it goes over the second peering, where it is prepended with AS4290006033.
Yes, that is true. I would add that one is not supposed to have different local ASNs for different BGP instances that form coherent BGP router, unless it is configured as BGP confederation or manually patched by filters. -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santiago@crfreenet.org) "To err is human -- to blame it on a computer is even more so."