On Tue, Dec 26, 2023 at 06:32:22PM +0100, Nico Schottelius via Bird-users wrote:
Hello everyone,
I was wondering how you typically handle announcing a decentralised infrastructure to its upstreams / the Internet and how you handle receiving your own routes again on other upstreams.
The scenario is as follows:
CUSTOMER PEERINGS 1 ------ AS P6 --- CUSTOMER PEERINGS 2 | / | / AS P5 ---- AS P10 --- UPSTREAM 1 | \ / \ | AS P7---\ \ |------------ AS P15 --- UPSTREAM 2 \ ---- UPSTREAM 3 \ ---- UPSTREAM 4
So essentialy the different AS are somewhat connected internally (*) (not full mesh due to physical constraints) and the objective is to announce all internal and all customer peerings to all upstreams.
Hello So i understand that AS P5 - AS P15 are different ASNs, but under common administrative control, and one of issues is that different AS path lengths conflicts with optimal path based on real topology? In that case i would suggest to use AIGP (RFC 7311), if you keep IGPs separate in each AS. To handle customer routes, i would just mark them with custom community on ingress to distinguish from other routes (e.g. for the purpose of propagation to upstreams). And another custom community for upstream routes (with similar behavior to OTC, RFC 9234). Of course, these communities must be filtered out on all ingresses before proper one is assigned. -- 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."