Teredo source addresses from 6to4 relay

[David Malone]

On Thu, May 10, 2007 at 10:17:32AM +0300, Pekka Savola wrote:
> I'm seeing some Teredo hosts trying to send packets to another Teredo 
> hosts through our 6to4 relay, and packets getting dropped due to uRPF.

> I wonder if other folks have seen stuff like this.

I've seen a related problem as an end-user in a network where I
have a 6to4 router and a SixXS tunnel. The address selection rules
on end hosts don't always match up the addresses right, so a
connection would end up with a 6to4 source address and a production
destination address. Our router would then forward that to the SixXS
tunnel, which would drop it because of uRPF. Using a better address
selection policy helped a lot (which is why it would be useful to
be able to distribute address selection policies, instead of having
to configure each host by hand).

However, your problem looks different 'cos it has correctly matched
the Toredo addresses, but then routed it over a 6to4 interface. Is
there any other consistent pattern that might identify which
implementation is doing this?

	David.