Subject: RE: W.G. Last Call on "Default Address Selection for IPv6"

From: "Hesham Soliman (ERA)" <[email-masked]>
Date: Tue, 5 Jun 2001 04:43:54 +0200

> > 
> > Based on our private discussion in Seattle,  think it would 
> > be useful to add a sending rule for mapped addresses 
> > as follows:
> > 
> > - If the destination address is an IPv4-mapped IPv6 address, and
> > - If the host is an IPv6-only host
> > the source address MUST be an IPv6-translated address. 
> 
> I think this makes sense as long as we preface it very clearly with
> 	Nodes that implement SIIT (does not apply to other nodes) ...
> 
	=> Agreed, that's where it would be relevant.

> Without that preface adding these rules will do nothing but adding confusion.
> 
	=> So if the node is not implementing SIIT then I guess communication
	is not possible in the scenario above. Is this a correct understanding ?

	Hesham
--------------------------------------------------------------------
IETF IPng Working Group Mailing List
IPng Home Page:                      http://playground.sun.com/ipng
FTP archive:                      ftp://playground.sun.com/pub/ipng
Direct all administrative requests to [email-masked]
--------------------------------------------------------------------

---

From: Erik Nordmark <[email-masked]>
Date: Tue, 5 Jun 2001 04:58:14 +0200 (CEST)

> 	is not possible in the scenario above. Is this a correct understanding ?

When an application on a dual-stack node sends to an IPv4-mapped
address the result is that the box is communicating using IPv4 packets.

When an application on an IPv6-only box which implements SIIT
does this the result is to send IPv6 packets (with an IPv4-mapped dest
and an IPv4-translatable source) to the SIIT translator box,
which will translate those to IPv4 packets.

When an application on an IPv6 only box which does not implement SIIT
sends to an IPv4-mapped address then communication doesn't happen -
presumably the stack would drop the packets and tell the application.

  Erik