RE: REVIEW NEEDED: draft-durand-v6ops-assisted-tunneling-requirements-00.txt

[Pekka Savola <pekkas@netcore.fi>]

On Tue, 4 May 2004, Christian Huitema wrote:
> > How widely is IP proto 41 forwarding deployed? If it is not much,
> > I suppose that forcing an extra layer of encapsulation would
> > not be that terrible... and also would allow for more than one
> > tunnel to go through the NAT box.
> > So, I do not think that detecting NAT proto 41 forwarding is
> > an important requirement.
> 
> You have to be concerned with the case when there are two hosts doing
> this behind the same NAT. At most one of them will get proto 41
> connectivity. If one got it and a second tries, the first one will loose
> it. The support issues are going to be interesting.

This is a good point to keep in mind, seems to clear call for using
UDP encapsulation in all the NAT traversal cases by default.  The
implementations might have a manual means to force using proto-41, but
even that might be far-fetched.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings