BGP Multihoming 2 providers full or partial?

Mon Jun 1 21:46:22 UTC 2015

On Mon, Jun 1, 2015 at 5:13 PM, Baldur Norddahl
<baldur.norddahl at gmail.com> wrote:
> This is only a problem if you use so called tier 1 transit providers.
>
> The smaller fish in the pond have multiple transits themselves and will
> there by always have an alternative route available.

Hi Baldur,

Cogent is not a tier 1 (not a "transit-free") provider last I heard.
Maybe that's changed, but they weren't back when they had the
week-long peering dispute with Sprint. Their business plan included
preventing their routes from reaching Sprint via paid transit. If you
were a customer of either carrier that week and you weren't multihomed
with full routes, you were not a happy camper.

"Always" is such a strong. Yes, you're at higher risk if all your
upstreams are "transit-free" but using only backbone providers who
have paid upstream transit in their mix is no panacea.

Regards,
Bill Herrin

-- 
William Herrin ................ herrin at dirtside.com  bill at herrin.us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>