Re: [v6ops] I-D Action: draft-mawatari-v6ops-464xlat-00.txt

Masanobu-san,

This is an interesting discussion and proposal. Few Q --

1. How is IPv4 address getting assigned to the host?
2. Could we not use an existing DHCP option to convey DNS server IPv4
address to the CLAT device, which can convey the DNSv4 address the same
way as IPv4 address is conveyed? If we could, then we would not need DNS
proxy function on CLAT. 
3. Section 7.4 requires CLAT device to have router function. What
happens if it is a typical host device (without any router function)?

~~~~~~~~~
7.4. DNS Proxy Implementation
   If a router implement CLAT function, it performs DNS Proxy for IPv4
   hosts and IPv6 hosts in end-user network.  It MUST provide name
   resolution with IPv6 transport.  It does not need DNS64 [RFC6147]
~~~~~~~~~~~~~~~

4.  In section 8, did you mean to say IPv4 -> IPv6 -> IPv4 translation
below? :-)
~~~~~~~~~~~~
...
   This 464XLAT architecture has two capabilities.  One is a IPv6 ->
   IPv4 -> IPv6 translation for sharing global IPv4 addresses, another
~~~~~~~~~

5. Section 7.7 (Auto IPv6 Prefix Assignment) could benefit from some
explicit recommendation (since the current text says source v6 prefix
assignment is done via DHCPv6-PD or another method, and destination IPv6
prefix assignment is via some method).

Cheers,
Rajiv

> -----Original Message-----
> From: v6ops-bounces@ietf.org [mailto:v6ops-bounces@ietf.org] On Behalf
Of
> Masanobu Kawashima
> Sent: Tuesday, January 24, 2012 12:21 PM
> To: Brian E Carpenter
> Cc: IPv6 Operations
> Subject: Re: [v6ops] I-D Action: draft-mawatari-v6ops-464xlat-00.txt
> 
> 
> Hi Brian,
> 
> Thank you for your comment.
> 
> I take your point. However, a CLAT can only learn the address of an
IPv6
> DNS recursive server through DHCPv6 (or other way). The CLAT can not
easily
> discover the address of an IPv4 DNS recursive server, and it has to
perform
> all DNS resolution over IPv6.
> 
> The CLAT can pass this IPv6 address to downstream IPv6 hosts, but not
to
> downstream IPv4 hosts. As such, the CLAT should implement a DNS proxy.
> 
> Regards,
> Masanobu
> 
> 
> >> 7.4.  DNS Proxy Implementation
> >>
> >>    If a router implement CLAT function, it performs DNS Proxy for
IPv4
> >>    hosts and IPv6 hosts in end-user network.
> >
> >Why is this necessary? As far as I can see, the client could use any
> >normal DNS server, because the A and AAAA records it needs are
completely
> >standard.
> >
> >Regards
> >   Brian Carpenter
> >
> >_______________________________________________
> >v6ops mailing list
> >v6ops@ietf.org
> >https://www.ietf.org/mailman/listinfo/v6ops
> 
> ========================================
>  NEC AccessTechnica, Ltd.
>  Product Development Department
>  Masanobu Kawashima
>  kawashimam@vx.jp.nec.com
>  http://www.necat.co.jp/
> ========================================
> 
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