RE: 6to4 vs forwarding IP proto41 in NAT

["Christian Huitema" <huitema@windows.microsoft.com>]

On Windows XP, with IPv6 enabled, if you ask to "share a link", the PC will behave as an IPv4 NAT (using ICS) and as a 6to4 router. So I guess there is at least one example of "NAT that is also a 6to4 router."

________________________________

From: owner-v6ops@ops.ietf.org on behalf of Tim Chown
Sent: Tue 7/15/2003 8:08 AM
To: v6ops@ops.ietf.org
Subject: Re: 6to4 vs forwarding IP proto41 in NAT



The advantage for plain proto41 forwarding is that you don't have to
decapsulate for it to work - just pass it on :)  The NAT web config
screen can just have a checkbox to forward proto41 and a field to
specify the RFC1918 address to forward it to.

But agreed if the vendor is implementing 6to4, there is no reason why they
couldn't choose to do this.

I wouldn't like to lose the ability to run a tunnel broker client inside my
network (for a host or network broker client) because of 6to4 support on
the router (which I applaud - and I'd be interested to know which vendors
are implementing it... Christian?)

Of course ideally we want IPv6 natively, but...

Tim

On Tue, Jul 15, 2003 at 08:01:45AM -0700, Alain Durand wrote:
> A NAT box could do the following when receiving an IPv6 packet
> encapsulated in IPv4 with proto 41:
>
> If IPv6 dst does not belong to the local 6to4 /48 prefix, forward
> internally,
> else decapsulate.
>
> Why will will not work?
>
>       - Alain.
>