BGP Peers as basis of available routes

Bill Woodcock woody at pch.net
Wed Oct 19 11:53:15 CDT 2011


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256


On Oct 18, 2011, at 11:46 PM, Nathanael C. Cariaga wrote:
> Is it safe to conclude that the web hosting provider's available routes would would depend on the peers who are advertising their AS / network?  (i.e if web hosting provider claims that they are peering with telco a, b, c but as seen from a third party looking glass, only C is seen advertising the web hosting provider network that would mean web hosting provider is effectively utilizing c as their upstream??)

Modulo a lot of nit-picking caveats, this would indicate that they are purchasing transit from C, while they may or may not be peering with A and B.  If a customer of A or B is able to reach them in a single AS-hop, but A and B are not advertising a route to C to looking-glasses or their own peers or transit providers, then A and B are peers, but not transit providers, to the web host.

> I would need to determine the web hosting provider who has the most number of peers and most number of transit providers?

A large number of transit providers has been shown, both theoretically and experimentally, to _decrease_ uptime, because of greater route-convergence times when there are more parallel paths to a destination.  Your mileage may vary, but the optimum number is usually somewhere around three transit providers.  The number of peers, though, and more to the point, the number of routes acquired through peering, is an excellent measure of how large and how long an ISP (in this case a web-hoster) has been in business.  That shouldn't be your only measure of quality, however.  It may be that reliability of power, competence of remote-hands, and flexibility to accommodate your needs are more important than how the packets get delivered.

                                -Bill




-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (Darwin)
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=zi6u
-----END PGP SIGNATURE-----




More information about the NANOG mailing list