From: "Hesham Soliman (EPA)" <[email-masked]>
Date: Fri, 15 Sep 2000 00:19:41 +1100

Hi George, Alan and Scott

I have a couple of questions on draft-tsirtsis-v4-over-mipv6-00.txt, 
How does an IPv6 MN inform its HA that it should intercept
any IPv4 packets coming to its IPv4 "home" subnet ?

I understand you are not using MIPv4 of course, so I guess
something needs to be done to trigger the HA to send proxy
ARP so it can receive packets destined to that (IPv6 MN's)
IPv4 address and map them to the MN's IPv6 home address. 

Also do you allow the IPv6 MN to acquire addresses from the 
foreign domain ? If you do then of course you would get better
route optimisation, but I know there are complications because
we have a similar problem to solve in our draft. 

Cheers,
Hesham

---

From: Francis Dupont <[email-masked]>
Date: Thu, 14 Sep 2000 16:02:11 +0200

In your previous mail you wrote:

=> it doesn't need to do this and there is no IPv4 home subnet.
The IPv4 traffic goes to the Tunnel End Point and is encapsulated &
(directly) routed to the Mobile Node. The IPv6 mobility layer
knows *nothing* about IPv4 and the IPv4 layer knows *nothing* about
mobility, the only interaction between them is the TEP should be
a correspondent and routing from the TEP to the MN should be optimized.

=> nothing is needed. TEP and HA functions can be done by one or
two boxes (same box is more complex and a bit more efficient).
I think you don't understand how the TEP gets IPv4 traffic:
it is the router for the IPv4 prefix. The HA is different, it is
a router attached to the link where is the prefix, if there is another
router on the link then the traffic can come through it (here again
you can make this impossible and get a small avantage with more
operational complexity).

   foreign domain ?

=> split functions -> full freedom (I can say the foreign domain is
an IPv6 notion which is not known by IPv4 too :-).

   If you do then of course you would get better
   route optimisation, but I know there are complications because
   we have a similar problem to solve in our draft. 
   
=> I believe this is easier in George's draft because the IPv4/TEP
selection is done by DSTM/DHCPv6 which can use or ignore mobile
IPv6 issues. (Current proposal doesn't provide a way for the DSTM
client to give the IPv4 address of its future IPv4 peer, it is an
issue or just a feature?)

Regards

[email-masked]