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

[Sebastian Kiesel <[e-mail]>]

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 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