IETF Logo Mail Archive

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

Masanobu Kawashima <kawashimam@vx.jp.nec.com> Wed, 25 January 2012 00:38 UTC

Return-Path: <kawashimam@vx.jp.nec.com>
X-Original-To: v6ops@ietfa.amsl.com
Delivered-To: v6ops@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id B0D9021F8566 for <v6ops@ietfa.amsl.com>; Tue, 24 Jan 2012 16:38:11 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 0.21
X-Spam-Level:
X-Spam-Status: No, score=0.21 tagged_above=-999 required=5 tests=[AWL=-0.300, BAYES_00=-2.599, HELO_EQ_JP=1.244, HOST_EQ_JP=1.265, J_CHICKENPOX_13=0.6]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ecvEXLt-Y8G5 for <v6ops@ietfa.amsl.com>; Tue, 24 Jan 2012 16:38:11 -0800 (PST)
Received: from tyo202.gate.nec.co.jp (TYO202.gate.nec.co.jp [202.32.8.206]) by ietfa.amsl.com (Postfix) with ESMTP id CF6E121F856D for <v6ops@ietf.org>; Tue, 24 Jan 2012 16:38:10 -0800 (PST)
Received: from mailgate3.nec.co.jp ([10.7.69.195]) by tyo202.gate.nec.co.jp (8.13.8/8.13.4) with ESMTP id q0P0c7ps024954; Wed, 25 Jan 2012 09:38:07 +0900 (JST)
Received: (from root@localhost) by mailgate3.nec.co.jp (8.11.7/3.7W-MAILGATE-NEC) id q0P0c5t09924; Wed, 25 Jan 2012 09:38:05 +0900 (JST)
Received: from mail01b.kamome.nec.co.jp (mail01b.kamome.nec.co.jp [10.25.43.2]) by mailsv.nec.co.jp (8.13.8/8.13.4) with ESMTP id q0P0c4r3014708; Wed, 25 Jan 2012 09:38:05 +0900 (JST)
Received: from shikibu.jp.nec.com ([10.26.220.2] [10.26.220.2]) by mail02.kamome.nec.co.jp with ESMTP id BT-MMP-530051; Wed, 25 Jan 2012 09:36:43 +0900
Received: from siznecatg159185 ([10.3.159.185] [10.3.159.185]) by mail.jp.nec.com with ESMTP; Wed, 25 Jan 2012 09:36:43 +0900
To: Brian E Carpenter <brian.e.carpenter@gmail.com>
In-reply-to: <4F1F12B3.4000905@gmail.com>
Message-Id: <20120125093643kawashimam@mail.jp.nec.com>
References: <4F1F12B3.4000905@gmail.com>
Mime-Version: 1.0
X-Mailer: StarOffice21/MailClient[4.65 Step9]
From: Masanobu Kawashima <kawashimam@vx.jp.nec.com>
Date: Wed, 25 Jan 2012 09:36:42 +0900
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Cc: IPv6 Operations <v6ops@ietf.org>
Subject: Re: [v6ops] I-D Action: draft-mawatari-v6ops-464xlat-00.txt
X-BeenThere: v6ops@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: v6ops discussion list <v6ops.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/v6ops>, <mailto:v6ops-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/v6ops>
List-Post: <mailto:v6ops@ietf.org>
List-Help: <mailto:v6ops-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v6ops>, <mailto:v6ops-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 25 Jan 2012 00:38:11 -0000

Hi Brian,

I agree with you completely.

The CLAT should be a DNS proxy to support IPv4 and IPv6 clients of the
CLAT and ensure that IPv6 end to end is preserved between the CLAT and
the IPv6 DNS sever.

The 464XLAT should also allow for the less optimal IPv4 DNS queries from
clients, which would require 464XLAT translation between the IPv4 hosts
and the IPv4 DNS servers. IPv6 enabled host may also directly query an
IPv6 DNS server.

We will add some clarifying language about this in the next revision.
Thank you for your helpful comments.

Regards,
Masanobu


>On 2012-01-25 06:21, Masanobu Kawashima wrote:
>> 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.
>
>But it should also be transparent to DNS queries over v4 or v6, if the
>client acquires a DNS server address by other means.
>
>Thanks
>   Brian
>
>> 
>> 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/                
>> ========================================
>> 
>> 

========================================
 NEC AccessTechnica, Ltd.               
 Product Development Department         
 Masanobu Kawashima                     
 kawashimam@vx.jp.nec.com               
 http://www.necat.co.jp/                
========================================

v2.23.0 | Report a Bug | By Email