[147606] in North American Network Operators' Group
Re: /128 IPv6 prefixes in the wild?
daemon@ATHENA.MIT.EDU (Mark Tinka)
Thu Dec 15 11:14:20 2011
From: Mark Tinka <mtinka@globaltransit.net>
To: nanog@nanog.org
Date: Fri, 16 Dec 2011 00:13:17 +0800
In-Reply-To: <F05D77A9631CAE4097F7B69095F1B06F597B5BC2@EX02.drtel.lan>
Reply-To: mtinka@globaltransit.net
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
--nextPart4893200.14ZsU1AEt4
Content-Type: Text/Plain;
charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
On Thursday, December 15, 2011 09:56:04 PM Brian Johnson=20
wrote:
> I think you will learn a lot of /128s from IGP, but not
> from eBGP. I consider the "wild" to be the DFZ or
> similar type of network and in that case, you should not
> see advertisements for anything longer than a /48. This
> is not hard and fast, but please correct me if I'm
> wrong.
Ideally, yes.
Good filtering (against your peers, customers and upstreams)=20
will ensure you keep anything longer than a /48 out of your=20
AS.
However, do note that if you provide customer-induced=20
automated blackhole routing (where customers attach an=20
"evil" community to an "evil" host route and send that to=20
you in an eBGP update because you expect it), that's one=20
other way to see /128's (or more appropriately, something=20
longer than a /48) across eBGP sessions with customers.
Also, if customers multi-home to you and they want to be=20
able to load share traffic across the various links between=20
their network and yours, you may be inclined to allow them=20
to send longer subnets that have a NO_EXPORT community=20
attached to them so that load sharing occurs within your=20
network for their inbound traffic, but de-aggregated routes=20
do not flood the rest of the Internet. This is another way=20
you could get "longer" routes into your network, with the=20
benefit of not polluting the global Internet.
Among other scenarios... :-).
Mark.
--nextPart4893200.14ZsU1AEt4
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.16 (GNU/Linux)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=07wp
-----END PGP SIGNATURE-----
--nextPart4893200.14ZsU1AEt4--
