nanog mailing list archives
Re: Multihomed route visibility
From: William Herrin <bill () herrin us>
Date: Mon, 4 Nov 2019 08:15:59 -0800
On Mon, Nov 4, 2019 at 8:13 AM Boyle, Patrick via NANOG <nanog () nanog org> wrote:
We are advertising the same prefix to ISP A & ISP B. When looking at various route servers across the world, I always see the path through ISP A in the BGP table, but most don’t show a path at all through ISP B (some do, like Oregon IX). I would expect any router with the full table to show both routes. Is this a consequence of how the route servers are peered up? Are they only displaying the preferred path? ISP Issue? Am I missing something?
Hi Patrick, Routers only propagate the *best* BGP route for the target network. You'll see both only where the AS received different best routes from its peers. Regards, Bill Herrin -- William Herrin bill () herrin us https://bill.herrin.us/
Current thread:
- Multihomed route visibility Boyle, Patrick via NANOG (Nov 04)
- Re: Multihomed route visibility Jared Mauch (Nov 04)
- Re: Multihomed route visibility William Herrin (Nov 04)