Re: [pcp] PCP Server Selection - Address Family Selection

[Dan Wing <[e-mail]>]

On Apr 26, 2014, at 2:37 PM, Sebastian Kiesel <[e-mail]> wrote:

> On Fri, Apr 25, 2014 at 06:42:53PM -0700, Dan Wing wrote:
>> 
>> On Apr 25, 2014, at 7:57 AM, Simon Perreault <[e-mail]> wrote:
>> 
>>> Le 2014-04-25 10:51, Sebastian Kiesel a écrit :
>>>> draft-ietf-pcp-server-selection-02  says in Section 3:
>>>> 
>>>>  1.  If the PCP client can use both address families when
>>>>      communicating to a particular PCP server, the PCP client SHOULD
>>>>      select the source address of the PCP request to be of the same IP
>>>>      address family as its requested PCP mapping (i.e., the address
>>>>      family of the Requested External IP Address).
>>>> 
>>>> 
>>>> What is the reason for saying it SHOULD use the same familiy as the
>>>> requested EXTERNAL IP address?  I think it would make more sense to use
>>>> the same familiy as the INTERNAL address (if there is a difference at
>>>> all).
>>> 
>>> +1
>>> 
>>> I stated this in my review.
>> 
>> The intent of the wording is to avoid NAT64 (or NAT46) where NAT44 or
>> no NAT was necessary at all. 
> 
> reasonable goal, but does text about that belong here?
> 
> this text is about PCP messages, and I think they should use the
> same address family as the actual user data flow on their side of
> the NAT.

If that avoids IP address family translation, sounds good to me.  Or is there some other value or purpose?

-d


>> If the wording is backwards, let's fix it.  I have now read it three
>> times, and the existing text seems to avoid NAT64.  In any event, yes,
>> there should be an explanation ("To avoid unnecessary IP address family
>> translation, ...").
> 
> Thanks
> Sebastian