> On Oct 31, 2019, at 3:12 PM, 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?
>
> Any help would be appreciated.
You will generally only see the best path. Most route servers don’t collect
any backup paths the routers may have, which could be quite extensive.
- Jared