Yep. Pretty common, especially with regional providers who are both at a peering exchange and who also buy transit.
Is particularly frustrating when AS C has configured their network to prefer customer routes instead of peers which is also really common. If I'm AS A and AS C is configured this way, my traffic will always go through AS B even though I'm peered with AS C directly. On Mon, Apr 7, 2025, 7:15 AM Sriram, Kotikalapudi (Fed) via NANOG < [email protected]> wrote: > Does the following ever happen in reality? Do you think it is strange and > unlikely? > > The lateral (i.e., non-transit) peer of an AS is also the transit provider > of the AS's transit provider. Example: AS A has AS B as a transit provider > and AS C as a lateral peer, and AS C is a transit provider of AS B. > > Thank you. > > Sriram > > > _______________________________________________ > NANOG mailing list > > https://lists.nanog.org/archives/list/[email protected]/message/NSV3GXEZ3UAMHLHSSEUMPXXZQGR65B44/ > _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/R7B3TUFKLYIA7IPY4TH43ZZ7MTABGJC2/
