RE: IPv6 Home Use to stimulate deployment over IPv4-NAT

["Tony Hain" <alh-ietf@tndh.net>]

So the case is a double nat? If it is just that the 'public' side of the
nat has a private address and needs to tunnel over IPv4 infrastructure,
isatap is the appropriate tool. 


-----Original Message-----
From: Bound, Jim [mailto:Jim.Bound@hp.com] 
Sent: Wednesday, February 12, 2003 11:15 AM
To: alh-ietf@tndh.net; v6ops@ops.ietf.org
Subject: RE: IPv6 Home Use to stimulate deployment over IPv4-NAT


Tony,

I may suggest alternative to Teredo but looking at that now technically.
But if Teredo works that is fine but many have issues with the
complexity.  So I will reserve comment on Teredo for now OK.  Not sure I
support it now.  We will see.

The home router cannot become a 6to4 router because the public address
may not be available or duplicated in practice is my assumption?  But
more than that an ecap of the packet with 6 proto-id is a simple
software engineering upgrade for very low end home routers and field
deliverable with a patch on the web is my belief, and 6to4 is far more
complex and may require an entire release. So the work we do here may be
two steps 1) first do simple encap, 2) eventually deploy 6to4 given the
home router can use the public address.  I am also worried of duplicate
public address for the home router for the nat which I have seen at home
and in hotels enough and in enough locations that I just have to look
further into it.  I am speaking with multiple providers now that do this
function to get the issues from the horses mouth not second hand.  I
will also speak with 2 well known home router vendors on my assumptions
for patches for upgrades.

Regards,
/jim



-----Original Message-----
From: Tony Hain [mailto:alh-ietf@tndh.net] 
Sent: Wednesday, February 12, 2003 1:55 PM
To: Bound, Jim; v6ops@ops.ietf.org
Subject: RE: IPv6 Home Use to stimulate deployment over IPv4-NAT


Maybe I misunderstood the scenario, but it looks like you are describing
a case where teredo is the appropriate choice. To restate; the ISP is
offering support for IPv6, including a tunnel endpoint to transit any
non-upgradable PE/CPE gear, though there is a nat in the path, so simple
IPv4 encaps using 6to4 or isatap will fail. If the nat can be upgraded,
it should become a 6to4 router. If not, it doesn't make sense to insert
yet another device to do tunneling, because the end nodes are capable of
doing it just as well.

Tony
-----Original Message-----
From: owner-v6ops@ops.ietf.org [mailto:owner-v6ops@ops.ietf.org] On
Behalf Of Bound, Jim
Sent: Wednesday, February 12, 2003 9:22 AM
To: v6ops@ops.ietf.org
Subject: IPv6 Home Use to stimulate deployment over IPv4-NAT


Folks,

I am hearing an need for home users for transition.  It could be this is
ipv6 wg work but will bounce it off here first.

Assume dominant NAT/VPN/Firewall routers in most homes for Internet
access.

Assume an upstream provider obtains IPv6 prefix to give to subscribers.

Assume home routers want to support IPv6 and will eventually but won't
move until they believe it can be used over provider networks.

Assume there is not enough Ipv4 address space for providers to give out
to all subscribers or cannot at reasonable cost.  But they can give the
subscriber an IPv6 prefix.  This means 6to4 or ISATAP won't work in this
scenario in the users home.

A solution (more on Teredo below) would be to figure a method for an
IPv6 on the homelan to be encaped in the NAT packet to the provider who
will decap that packet and send to the IPv6 destination and recall the
state to the NAT user upon receiving packets back so the session can be
established with the home user over the net.

This is quick for now as a thought.

The home user network encaps the IPv6 packet at NAT with Protocol ID
equivalent to "6".  The provider then takes that packet and decaps at
their edge and uses native IPv6 or 6to4 to encap that packet to where
the IPv6 service is located.  I realize this has many assumptions and I
would work on those with some other folks interested in this problem.  

I am re-reading Teredo now and working to see if it is addendum to
Teredo or completely different solution.  I think it is a different
solution and possibly much simpler.  I also believe this solution we are
looking at can do e2e IPsec over the IPv4-NAT.

This would be a minor initial update for the home router vendors and
basic IPv6 edge tunneling for the Provider.  Also I think a
tunnel-broker could be used by the Provider to help set this up for
users too.  The code for the home router on my first analysis could also
be a firmware upgrade that is down loadable.

Could I get others opinions and thoughts on this before I and some
others jump in here.

thanks
/jim