List of Teredo servers and teredo relays

khatfield at khatfield at
Sat Sep 11 22:18:57 UTC 2010

Thanks for the explanation.

And Owen: thanks, I just thought most networks/facilities (colo/private) should be close to ipv6 now days. At least capable, maybe not configured.

I think I was just making an assumption so thanks for the info.
------Original Message------
From: Jeff Kell
To: Kevin Hatfield
Subject: Re: List of Teredo servers and teredo relays
Sent: Sep 11, 2010 3:22 PM

 On 9/11/2010 3:29 PM, khatfield at wrote:
> I may be missing the point here completely but to me Teredo just seems like a glorified hack/workaround for a bigger problem. Isn't is better (yes less cost-effective) to just upgrade equipment?
> I really don't see the advantage here. Maybe someone can explain away my ignorance to the concept?

Teredo is a "last-ditch"  solution, but unfortunately in the Microsoft
world, and acceptable and preferable solution over IPv4.

Pure speculation, but the IPv6 efforts of many (looking at current
MacOS, Windows, and a growing segment of PDAs/phones) are making
tremendous effort to obtain "some" form of IPv6 connectivity.  This
makes sense if there were (a) only IPv6 connectivity at the client
endpoint, or (b) only IPv6 connectivity at the service endpoint.  That
would insure things would work if either case were true.

What is currently "breaking" things is the preference of IPv6 over
IPv4.  If you're running a default Win2K8 active directory, it's
publishing all of it's goodies for login in IPv6 form complete with AAAA
address records.  If your network isn't end-to-end IPv6 compliant, but
some Win7 client across the hall (on another subnet) has found *any*
IPv6 connectivity (6to4, Teredo, doesn't matter how good/bad/ugly/slow),
it is going to try to communicate with the domain controller over that
IPv6 connection.  I have seen this in action, and stacks of trouble
tickets of slow / intermittent / no connectivity with the domain.

As it currently stands, if you're not 100% end-to-end IPv6 ready with
compliant transport, these "preferences" break or cripple things.

Of course, this all may be by IPv6 design (make it so horribly painful
not to accomodate to push you to provide better alternatives) :-)


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