Re: Comment/Question on draft-yegin-dmm-ondemand-mobility

Hi Julien,

Thank you for the feedback.

"Prefer" has the following semantic: Give me one IP address of this type, if one is available.
"Required" has the additional semantic: Try to configure one, is none is available.

So, "prefer" does not cover functionality we are seeking.

Alper


On Aug 14, 2013, at 11:12 PM, Julien Laganier wrote:

> Hi Alper,
> 
> I have one comment/question below.
> 
> The reason 5014 defines preference rather than requirements is, it was
> expected that many application only have preferences rather than a
> hard requirements, thus it makes sense to provide N IPV6_PREFER_SRC_*
> values for the socket option to allow application to express
> preferences for the N type of addresses. Doing it in this way wouldn't
> lead to a communication failure if preference couldn't be fulfilled,
> e.g., at time of connect() or send().
> 
> For those applications that have a hard requirement, they can first
> express their preference, and once the kernel has selected an address
> based on the preference at connect() or bind2addrsel()  invocation,
> verify that their preference satisfy the requirement with the
> is_srcaddr call. See http://tools.ietf.org/html/rfc5014#section-13 for
> the details.
> 
> Given the application with hard requirement can be supported as above,
> there was no need to define another N IPV6_REQUIRE_SRC_* values...
> 
> This seems to apply to your draft too, doesn't it?
> 
> If so you would only need to define one new value in addition to the
> two existing ones that are relevant to your problem statement:
> 
> - existing IPV6_PREFER_SRC_HOME [RFC5014] for home anchored
> 
> - existing IPV6_PREFER_SRC_COA [RFC5014] for unanchored
> 
> - new IPV6_PREFERE_SRC_VISITED [I-D.yegin-dmm-ondemand-mobility] for
> access anchored
> 
> what do you think?
> 
> Regards,
> 
> --julien
> 
> On Thu, Jul 18, 2013 at 7:17 AM, Alper Yegin <[email protected]> wrote:
>> Hey Julien,
>> 
>> How is it going?
>> 
>> Did you have a chance to read our new I-Ds?
>> 
>> http://www.ietf.org/id/draft-yegin-dmm-cnet-homing-00.txt
>> 
>> http://www.ietf.org/id/draft-yegin-dmm-ondemand-mobility-00.txt
>> 
>> I'd appreciate if you can take a look at them and share your comments --
>> online or offline, either way is fine.
>> 
>> 
>> Thank you and see you in Berlin.
>> 
>> Alper