[192048] in North American Network Operators' Group
Re: nested prefixes in Internet
daemon@ATHENA.MIT.EDU (Owen DeLong)
Tue Oct 11 18:58:15 2016
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <a8761846-e22e-6fee-cadf-12e48ad4a878@gmail.com>
Date: Tue, 11 Oct 2016 15:58:09 -0700
To: Baldur Norddahl <baldur.norddahl@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
> On Oct 10, 2016, at 14:59 , Baldur Norddahl =
<baldur.norddahl@gmail.com> wrote:
>=20
>=20
>=20
> Den 10/10/2016 kl. 22.27 skrev Owen DeLong:
>> Not true=85 There are myriad reasons that the /24 might not reach a =
network peered with ISP-A, including the possibility of being a =
downstream customer of a network peered with or buying transit from =
ISP-A. In the latter case, not an issue, since it=92s paid transit, but =
in the former (peered, not transit), again, ISP-A is probably not super =
excited to carry traffic that someone isn=92t paying them to carry.
>>=20
>=20
> But ISP-A is in fact being paid to carry the traffic. Supposedly ISP-B =
has a paid transit relation to ISP-A. In the case the transit link is =
down ISP-A might have to transport the traffic through a less profitable =
link however.
Which isn=92t really in the agreement between ISP-B and ISP-A unless it =
was specifically (and unusually) negotiated.
Also, you=92re assuming that the leased space came with a transit =
agreement. In many cases, address leases don=92t, so consider the =
additional scenario where ISP-B leases addresses from ISP-A, but has =
transit contracts with ISP-C and ISP-D but no connection at all to =
ISP-A.
> I know that if ISP-A was my network I would be making money even with =
the transit link down. Yes I might have to transport something out of my =
network through one of my transits, but outbound traffic is in fact free =
for us because we are heavy inbound loaded.
Yes, but it doesn=92t help if it also came in on a transit link. Any =
traffic you both receive and transmit on transit costs you money pretty =
much no matter who you are.
Owen
