[111369] in North American Network Operators' Group
RE: Private use of non-RFC1918 IP space (IPv6-MW)
daemon@ATHENA.MIT.EDU (TJ)
Wed Feb 4 20:53:03 2009
From: "TJ" <trejrco@gmail.com>
To: "'NANOG list'" <nanog@nanog.org>
In-Reply-To: <76C8FA39-19A6-4C5B-87DC-9789B39590EC@ianai.net>
Date: Wed, 4 Feb 2009 20:45:22 -0500
Errors-To: nanog-bounces@nanog.org
>> On Mon, Feb 2, 2009 at 9:35 PM, Patrick W. Gilmore
>> <patrick@ianai.net>wrote:
>>
>>> Except the RIRs won't give you another /48 when you have only used
>>> one trillion IP addresses.
>>
>> Of course they will! A /48 is only the equivalent of 65536 "networks"
>> (each network being a /64). Presuming that ISPs allocate /64 networks
>> to each connected subscriber, then a /48 is only 65k subscribers, or
>> say around a maximum of 200k IP addresses in use at any one time
>> (presuming no NAT and an average of 3-4 IP-based devices per
>> subscriber)
>>
>> IPv4-style utilization ratios do make some sense under IPv6, but not
>> at the address level - only at the network level.
>
>First, it was (mostly) a joke.
>
>Second, where did you get 4 users per /64? Are you planning to hand each
>cable modem a /64?
No, we should hand each home a /56 (or perhaps a /48, for the purists out
there) - allowing for multiple segments (aka subnet, aka links, etc.). Note
- the actual number of hosts is irrelevant; the 64 bits on the host side of
the address are not meant to encourage 18BB hosts/segment.
Oh, and utilization should be based on /56s anyway.
/TJ
