Re: [v6ops] Fwd: I-D Action: draft-ietf-v6ops-unique-ipv6-prefix-per-host-07.txt

[DY Kim <[e-mail]>]

Thanks.

Then… is the number ‘/64’ of this document a MUST or MAY?

For example, I might like to assign to each nodes in my site /96 prefix instead of /64.

Is this prohibited by this document? Or is ‘/64’ mentioned in the document only an example?

Regards,
DY








> On 4 Aug 2017, at 12:48, Mark Smith <[e-mail]> wrote:
> 
> On 4 Aug 2017 12:47, "DY Kim" <[e-mail]> wrote:
> 
>> Taken.
> 
>> A follow-on question:
> 
>> Assume the site under my management purview is assigned a /48 prefix from an upstream provider. Can I apply this BCP to the devices in my site?
> 
> 
> No reason you couldn't, how you use those 64k /64s is up you and would
> be hidden from the provider.
> 
> I can imagine some sites might have a mix of per-host /64s as well as
> a number of /64s with multiple hosts (that is, today's model), perhaps
> where some of the devices are unlikely to benefit from having their
> own /64 e.g., low powered IoT/sensor devices perhaps. A residential
> network might have a mix.
> 
> 
>> I think that’s at least technically possible. And I don’t see a text in the doc which prevents me from doing that on my own autonomous decision and responsibility. Right?
> 
> Even if there was text in the document that stated it was prohibited,
> I don't see how it could be policed, or be worth paying the cost of
> developing a system to try to police it.
> 
> 
> Regards,
> Mark.
> 
> 
> 
> 
>> On 4 Aug 2017, at 11:39, Mark Smith <[e-mail]> wrote:
>> 
>> On 4 August 2017 at 11:53, DY Kim <[e-mail]> wrote:
>>> In the 2nd para of Sec. 4, it reads:
>>> 
>>> “… a Unique IPv6 prefix (currently a /64 prefix)…”
>>> 
>>> Assuming that there’d be at some place upwards where a /48 prefix would be
>>> present, which prefix length is up to a common practice for ISPs in
>>> assigning a prefix to a site, does the above spec means:
>>> 
>>> o the maximum number of devices that the proposed scenario can accommodate
>>> is 64K (2**16; 64 - 48 = 16)?
>>> 
>> 
>> (Not speaking on the authors behalf)
>> 
>> If you only received a /48 for your site, then yes, that would be the
>> upper limit on how many devices this method supported.
>> 
>> However, the scenario being described is one of a service provider,
>> and they will get at least a /32 from their RIR, meaning in theory the
>> maximum number of hosts they can support is 4 billion (!). They could
>> get larger than /32 if they needed to if it became too small.
>> 
>> In this scenario a "site" is really the individual host, rather than a
>> boundary of a group of subnets at a site. /48 or /56 are common
>> aggregation boundaries for a multi-subnet site, so they don't really
>> apply here. The service provider could internally aggregate the /64s
>> at any where they need to between e.g. /32 and /63 to suit their
>> routing protocol scaling.
>> 
>> So in short, /48 is not constraining this solution because /48 doesn't apply.
>> 
>> Regards,
>> Mark.