[167553] in North American Network Operators' Group
Re: IPv6 /48 advertisements
daemon@ATHENA.MIT.EDU (Edward Dore)
Wed Dec 18 17:48:16 2013
From: Edward Dore <edward.dore@freethought-internet.co.uk>
In-Reply-To: <CAJvB4tnBzSxqFACQR30Wv0ojq7H3=yvdsNtTwP0YzdZ4kGyN_w@mail.gmail.com>
Date: Wed, 18 Dec 2013 22:47:37 +0000
To: Blake Dunlap <ikiris@gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>,
Cliff Bowles <cliff.bowles@apollogrp.edu>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Yes, from a filtering point of view a /48 in IPv6 is pretty similar to a =
/24 in IPv4, as perfectly illustrated by the two links in my post=85
My point was that if you are getting the carrier to do the announcement =
for you then they can announce an aggregated /48 prefix and then break =
that up inside their network (if their internal policies allow it) to =
give the OP whatever prefix length per site they have decided on. The =
carrier only needs to carry the more specific prefixes on their backbone =
and the rest of the internet sees the aggregated prefix.
This all depends on the architecture of the OP=92s network and what =
services they are buying from the carrier.
Of course, just getting a /48 per site and doing it properly would be =
the ideal scenario.
Edward Dore=20
Freethought Internet=20
On 18 Dec 2013, at 16:32, Blake Dunlap <ikiris@gmail.com> wrote:
> Regardless of the carriers, you'll find most ASs on the internet only =
listen to /48 or larger. So even if you get your prefixes accepted by =
your provider, don't assume you can get anywhere, or have your packets =
not fall in to uRPF blackholes randomly without a larger aggregate =
announcement.
>=20
> -Blake
>=20
>=20
> On Wed, Dec 18, 2013 at 10:22 AM, Edward Dore =
<edward.dore@freethought-internet.co.uk> wrote:
> If you=92re talking about announcing each location separately, then =
RIPE have a couple of useful articles about prefix visibility on Ripe =
Labs:
>=20
> =
https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48=
-filtering
> https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths
>=20
> Otherwise I guess you=92ll need to talk to your chosen carrier(s) =
about aggregating your space for you, which will come down to their =
policies on what routes they will carry internally.
>=20
> Edward Dore
> Freethought Internet
>=20
> On 18 Dec 2013, at 16:11, Cliff Bowles <cliff.bowles@apollogrp.edu> =
wrote:
>=20
> > I accidentally sent this to nanog-request yesterday. I could use =
some feedback from anyone that can help, please.
> >
> > Question: will carriers accept IPv6 advertisements smaller than /48?
> >
> > Our org was approved a /36 based on number of locations. The bulk of =
those IPs will be in the data centers. As we were chopping up the =
address space, it was determined that the remote campus locations would =
be fine with a /60 per site. (16 networks of /64). There are usually =
less than 50 people at the majority of these locations and only about 10 =
different functional VLANs (Voice, Data, Local Services, Wireless, Guest =
Wireless, etc...).
> >
> > Now, there has been talk about putting an internet link in every =
campus rather than back hauling it all to the data centers via MPLS. =
However, if we do this, then would we need a /48 per campus? That is =
massively wasteful, at 65,536 networks per location. Is the /48 =
requirement set in stone? Will any carriers consider longer prefixes?
> >
> > I know some people are always saying that the old mentality of =
conserving space needs to go away, but I was bitten by that IPv4 issue =
back in the day and have done a few VLSM network overhauls. I'd rather =
not massively allocate unless it's a requirement.
> >
> > Thanks in advance.
> >
> > CWB
> >
> >
> >
> >
> > ________________________________
> > This message is private and confidential. If you have received it in =
error, please notify the sender and remove it from your system.
> >
>=20
>=20
