Re: comments on draft-itojun-v6ops-v4mapped-harmful-00.txt

[Jun-ichiro itojun Hagino <itojun@iijlab.net>]

	(since this is transition tool discussion replies to ngtrans please)

>The assumptions behind SIIT is that the node is dual stack (the protocols
>as well as the applications) but the node  doesn't have a permanent IPv4
>address and the local network infrastructure does not support IPv4.
>With those assumptions there aren't any strange requirements on the devices
>(ignoring the AH suggestion in the RFC:-); the ftp implementation on a 
>dual stack node already needs to support old stuff when communicating with
>IPv4 addresses.

	if the above assumption is true, what do you intend to do about the
	dual use of IPv4 mapped address?  telnet client on dual stack machine
	would make a send(2) request to ::ffff:a.b.c.d, which will be captured
	by an AF_INET6 socket, and goes out of the node as IPv4 packet.
	there's no documented way in which ::ffff:a.b.c.d would go out as IPv6
	packet.  either RFC2553 API does not work, or SIIT dose not work.

itojun