[ppml] 2005-1 status
owen at delong.com
Tue Feb 7 06:32:30 EST 2006
--On February 7, 2006 10:06:11 AM +0000 Michael.Dillon at btradianz.com wrote:
>> Nor are we supposed to be doing our best to waste IPv6 space by holding
>> an unstated "/48 per location" policy when a typical location only needs
>> or two /64s.
> In fact you are wrong. According to RFC 3177
> we are supposed to be giving a /48 unless we are absolutely
> certain that the site will never ever need more than one subnet.
> Therefore, if the site needs 2 subnets today, then they qualify
> for a /48 with no questions asked. In fact, if they might add a
> second subnet in the next 10 years, they also qualify for a
> /48 today.
> Here is a quote from RFC 3177:
> 4. Conservation of Address Space
> The question naturally arises whether giving a /48 to every
> subscriber represents a profligate waste of address space. Objective
> analysis shows that this is not the case. A /48 prefix under the 001
> Global Unicast Address prefix contains 45 variable bits. That is,
> the number of available prefixes is 2 to the power 45 or about 35
> trillion (35,184,372,088,832).
It also does not define the term site, but, implies in the paragraph:
It is not obvious, however, that all edge networks are likely to be
recursively subnetted; a single PC in a home or a telephone in a
mobile cellular network, for example, may or may not interface to a
subnetted local network. When a network number is delegated to a
place that will not require subnetting, therefore, it might be
acceptable for an ISP to give a single 64-bit prefix - perhaps shared
among the dial-in connections to the same ISP router. However this
decision may be taken in the knowledge that there is objectively no
shortage of /48s, and the expectation that personal, home networks
will become the norm. Indeed, it is widely expected that all IPv6
subscribers, whether domestic (homes), mobile (vehicles or
individuals), or enterprises of any size, will eventually possess
multiple always-on hosts, at least one subnet with the potential for
additional subnetting, and therefore some internal routing
capability. In other words the subscriber allocation unit is not
always a host; it is always potentially a site. The question this
memo is addressing is how much address space should be delegated to
That the definition could extend to an enterprise of any size being
treated as a "site". As such, I don't think you have proven your
>> If an applicant came back with reasonable justification why their site
>> org) needed more than a /48 total, even to the level of a /48 per
>> I'm confident ARIN would go along with it. There is nothing in the
>> that prohibits such if it's justified.
> Justification means different things in the IPv4 world and the IPv6 world.
> We need to be careful not to confuse the two.
Yes... In the IPv6 world, it means the needed number of subnets and has
virtually no relationship to host needs whatsoever. I think that ARIN
staff can be considered non-idiotic and would appropriately take this
fact into account.
If this message was not signed with gpg key 0FE2AA3D, it's probably
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