[108749] in North American Network Operators' Group
Re: IPv6 Wow
daemon@ATHENA.MIT.EDU (Mark Andrews)
Thu Oct 23 19:52:20 2008
To: Alain Durand <alain_durand@cable.comcast.com>
From: Mark Andrews <Mark_Andrews@isc.org>
In-reply-to: Your message of "Thu, 23 Oct 2008 18:46:05 EDT."
<C52676ED.1C53A%alain_durand@cable.comcast.com>
Date: Fri, 24 Oct 2008 10:52:00 +1100
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
In message <C52676ED.1C53A%alain_durand@cable.comcast.com>, Alain Durand writes
:
>
>
>
> 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.
>
> - Alain.
Longest match to select destination address without knowlege of
the prefix lengths involved is bogus.
Applying a /32, /48 and /64 prefix break points to addresses
in 2001::/16 and 2003::/16 and a /16, /48 and /64 to addresses
in 2002::/16 will produce reasonable but not perfect results.
That's ISP, SITE and LINK level prefix break points. 6to4
can be seen as one ISP with a /16. Note you only need to
configure the break points for the address space you are
using.
We need automate the dissemination of these values within a
ISP to the customers so they can correctly configure their
address selection rules.
Mark
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: Mark_Andrews@isc.org
