[108750] in North American Network Operators' Group
Re: IPv6 Wow
daemon@ATHENA.MIT.EDU (Joe Abley)
Thu Oct 23 23:09:14 2008
From: Joe Abley <jabley@hopcount.ca>
To: Alain Durand <alain_durand@cable.comcast.com>
In-Reply-To: <C52676ED.1C53A%alain_durand@cable.comcast.com>
Date: Thu, 23 Oct 2008 23:08:18 -0400
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On 23 Oct 2008, at 18:46, Alain Durand wrote:
> On 10/23/08 6:39 PM, "Tony Hain" <alh-ietf@tndh.net> wrote:
>
>> A properly
>> implemented client will do the longest prefix match against that
>> set, so a
>> 6to4 client will go directly to the content provider's 6to4 router,
>> while a
>> native client will take the direct path.
>
> Not quite.
> Say the server has native IPv6 address 2001::1 and 6to4 IPv6 2002::X.
> Say the client has native IPv6 address 2003::1 and 6to4 IPv6 2002::Y.
> Longest prefix match will choose 6to4 over native IPv6. Not good.
Surely the longest prefix only wins over prefixes that cover the long
prefix.
What you seem to be suggesting is that a client will somehow be able
to deduce the prefix length for two bare v6 addresses received from
the DNS, and will choose the one with the longest prefix first. That
seems unlikely to be the case in general.
Joe
