6to4 question

[Brian E Carpenter]

Well, the 6to4 specification is written to forbid any possibility
of injecting the IPv4 routing table into the IPv6 routing table.
As Francis says, people think this would be evil. With today's
routers, they would most likely run out of memory and CPU.
(Remember that an IPv6 route entry is ~4 times bigger.)

So the answer is: you could do it, and it would probably work for
a few cases, but you MUST NOT.

  Brian

Francis Dupont wrote:
> 
>  In your previous mail you wrote:
> 
>    I have been trying the 6to4 protocol and studying the related documents.
> 
>    In the draft "draft-ietf-ngtrans-6to4-06.txt",  there is description as
>    the following:
> 
>                On its native IPv6 interface, the relay router MUST
>    advertise a route
>                 to 2002::/16. It MUST NOT advertise a longer 2002:: routing
>    prefix on
>                 that interface.
> 
>    I have doubt about this.
> 
> => I have no doubt about this because we DON'T want to have the
> whole IPv4 routing table injected into 2002:xx:yy::/48 stuff...
> Whether the MUST NOT is enough is another question (I don't think so
> then I proposed to swap the bytes of the embedded IPv4 address in
> 6to4 prefixes in order to make this impossible. Perhaps I was/am
> too pessimistic... We'll see).
> 
> Francis.Dupont@enst-bretagne.fr