Re: [Softwires] MAP and 4rd - Relationship with Single translation

[Xing Li <[e-mail]>]

Hi, Remi,

于 2012/3/19 21:22, Rémi Després 写道:
> Hi, Xing,
>
> I look forward to face to face discussions in Paris if we don't 
> clarify everything before that (I will be busy on something else in 
> the next 3 days).
>
>
> Le 2012-03-18 à 23:39, Xing Li a écrit :
> ...
>>>
>>>  A key point is that 4rd doesn't prevent a 4rd-capable dual-stack CE 
>>> node, when it receives no 4rd mapping rule, to exercise single 
>>> translation.
>>>  Actually, I believe that using for this the BIH of RFC6535 is both 
>>> sufficient and recommendable.
>>>  Translated IPv4 packets, because they are sent from CE nodes to 
>>> DNS64 synthesized addresses, are appropriately routed to their 
>>> destinations. (It can be via the NAT64-CGN if needed, or via more 
>>> direct paths if possible.)
>>> Anything missed?
>>
>> Sorry, this is a misunderstanding.
>> Hint: Single translation and double translation are based on the same 
>> mapping rule in the CERNET2 deployment.
>
> I am well aware of this, but this doesn't explain why 4rd mapping 
> rules similar to those of CERNET2 wouldn't have, like MAP-T, "IPv4 to 
> IPv6 communication (single translation) supported".
>
> As said in RFC6219, CERNET hosts have their IPv6 addresses configured 
> "via manual configuration or stateful autoconfiguration via DHCPv6".
> Hosts can therefore be assigned Interface IDs that have the 4rd-u 
> format (with V octet and CNP).
>
> Now, when both addresses happen to be checksum neutral, RFC6145 
> translation doesn't modify L4 data, so that it doesn't matter whether 
> the DS node has used 4rd-u header mapping or single translation.
> Thus, IPv6-only hosts can exchange packets with IPv4 applications of 
> 4rd CE nodes.

Sorry, it still a misunderstanding. one BRM per CPE, or ONE IPv6 for host.

Regards,

xing

>
> Regards,
> RD
>
>
>
>
>
>
>
>> Regards,
>>
>> xing
>>
>>
>>>
>>> Regards,
>>> RD
>>>
>>>
>>>
>>>
>>>
>>>> Regards,
>>>>
>>>> xing
>>>>
>>>>
>>>>>
>>>>> Regards,
>>>>> RD
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Le 2012-02-10 à 04:28, Xing Li a écrit :
>>>>> ...| | | | |
>>>>>>>>    |  5 | IPv6 web caches work for IPv4        |  Y  |  N  |  Y  |  N  |
>>>>>>>>    |    | packets                              |     |     |     |     |
>>>>>>> suggest you rename to "IPv4 to IPv6 communication (single translation) supported"
>>>>>>>
>>>>>>
>>>>>> (2) More clarification should be added here. I am not sure 4rd-H 
>>>>>> can support single translation.
>>>>>>
>>>>>> (a) According to (1), 4rd-H does not perform header translation 
>>>>>> defined by RFC6145.
>>>>>>
>>>>>> (b) In the softwire mailing list, it seems that 4rd-H cannot 
>>>>>> support single translation.  See the thread containing 
>>>>>> http://www.ietf.org/mail-archive/web/softwires/current/msg03324.html 
>>>>>> and other posts.
>>>>>>
>>>>>> (c) If 4rd-H cannot support single translation, then "IPv6 web 
>>>>>> caches work for IPv4 packets" requires special configurations, it 
>>>>>> cannot do IPv6 web caches for non 4rd-H packets.
>>>>>
>>>>> ...
>>>>>
>>>>>> (5) I would like to see the details of how 4rd-H handles ICMP and 
>>>>>> ICMP error messages. In the softwire mailing list there were some 
>>>>>> discussions. See the thread containing 
>>>>>> http://www.ietf.org/mail-archive/web/softwires/current/msg03324.html 
>>>>>> and other posts.Please add
>>>>>>
>>>>>> | 17 | Handle ICMP (RFC6145) | Y | n/a | ? | ? |
>>>>> ...
>>>>>
>>>>
>>>
>>
>>
>