[v6ops] Re: [IPv6]Re: Is the P flag even necessary? M flag already does enough (Re: Re: A detail review of draft-ietf-6man-pio-pflag-04)

[Timothy Winters <[e-mail]>]

Hi Ted,

I almost made that modification and can't think of a great reason not to.

OLD:
LPD-8: The IPv6 CE Router SHOULD by default provision IA_PD IA prefixes
with a prefix-length of 64.

New:
LPD-8: The IPv6 CE Router MUST provision IA_PD prefixes with a
prefix-length of 64 unless configured to different prefix-length by the
user.

~Tim

On Tue, Aug 6, 2024 at 11:32 AM Ted Lemon <[e-mail]> wrote:

> Yes, much better. Thanks!
>
> Why SHOULD and not MUST?  What is the case where they would not do this?
>
> Op di 6 aug 2024 om 11:26 schreef Timothy Winters <[e-mail]>
>
>> Hi Ted,
>>
>> How about this:
>>
>> OLD:
>> LPD-8: The IPv6 CE Router SHOULD by default provision IA_PD IA prefixes
>> with a prefix-length of 64.
>>
>> New:
>> LPD-8: The IPv6 CE Router SHOULD provision IA_PD prefixes with a
>> prefix-length of 64 unless configured to different prefix-length by the
>> user.
>>
>> I'll make this change in the next revision.
>>
>> ~Tim
>>
>> On Tue, Aug 6, 2024 at 10:49 AM Ted Lemon <[e-mail]> wrote:
>>
>>> What I’m saying is that the text is ambiguous because you don’t say what
>>> “by default” means. I am one of the people who wants to get rid of the
>>> hierarchical model.
>>>
>>> Op di 6 aug 2024 om 09:05 schreef Timothy Winters <[e-mail]>
>>>
>>>> Hi Ted,
>>>>
>>>> On Mon, Aug 5, 2024 at 2:30 PM Ted Lemon <[e-mail]> wrote:
>>>>
>>>>> On Mon, Aug 5, 2024 at 11:16 AM Timothy Winters <[e-mail]>
>>>>> wrote:
>>>>>
>>>>>> v6ops has a draft for PD on the LAN to improve this situation.
>>>>>>
>>>>>> https://datatracker.ietf.org/doc/draft-ietf-v6ops-cpe-lan-pd/
>>>>>>
>>>>>> Please feel free to send comments, we are about to do WGLC on it.
>>>>>>
>>>>>
>>>>> Hey, Tim. I hadn't read the document in a while. I see this text in
>>>>> the last requirement:
>>>>>
>>>>> The IPv6 CE Router SHOULD by default provision IA_PD IA prefixes with
>>>>> a prefix-length of 64.
>>>>>
>>>>> I read this as "if the DHCP client doesn't specify a narrower prefix,
>>>>> the CE router SHOULD .. 64"
>>>>>
>>>>> Is that what you intended? If not, I think you need to say more. If
>>>>> that is what you intended, this won't work, because if we stack CE routers,
>>>>> I expect every CE router to ask for a /48, rather than not specifying, and
>>>>> that would mean that we'd always delegate the narrowest remaining subset of
>>>>> the outer CE router's delegation to the first inner router that makes a
>>>>> request.
>>>>>
>>>> That's what the working group wanted.  The original version of this
>>>> document had more text about how to support hierarchical or flat models.
>>>> After a round or two discussion what came out of that was routers behind a
>>>> CE Router are no longer a CE Router as they aren't at the customer edge.
>>>>  The draft reflects that general consensus, that leans towards deploying a
>>>> flat model as opposed to hierarchical, which is where the /64 length
>>>> derives from.
>>>>
>>>> I think it may be time for another document to specify what to do if
>>>> you're a Internal Router (but not SNAC).  We could include all the flat
>>>> model text for becoming a DHCP Relay and giving out IA_PD with /64 from the
>>>> customer edge.
>>>>
>>>>>
>>>>>
>>>>