[192030] in North American Network Operators' Group
Re: nested prefixes in Internet
daemon@ATHENA.MIT.EDU (Niels Bakker)
Mon Oct 10 13:28:07 2016
X-Original-To: nanog@nanog.org
Date: Mon, 10 Oct 2016 19:24:45 +0200
From: Niels Bakker <niels=nanog@bakker.net>
To: nanog@nanog.org
Mail-Followup-To: nanog@nanog.org
In-Reply-To: <3367963c-92ca-c5c5-10a5-b640672d35e0@gmail.com>
Errors-To: nanog-bounces@nanog.org
* r.engehausen@gmail.com (Roy) [Mon 10 Oct 2016, 19:19 CEST]:
>I don't think I ever said that ISP-B would announce the /19. That
>would only be announced by ISP-A. ISP-B would only announce the /24
>that has been delegated to it.
>
>If the ISP-A/ISP-B link goes down then the /24 would be seen only
>via ISP-C which is the desired result.
What if ISP-A then receives traffic inside its /19 destined for
ISP-B's /24? It will have to send it over transit and won't bill
ISP-B for that traffic. You cannot expect 100% of the rest of the
Internet to honour the more specific all the time.
-- Niels.
