Private use of non-RFC1918 IP space (IPv6-MW)
Patrick W. Gilmore
patrick at ianai.net
Wed Feb 4 18:02:56 CST 2009
On Feb 4, 2009, at 6:56 PM, Scott Howard wrote:
> On Mon, Feb 2, 2009 at 9:35 PM, Patrick W. Gilmore
> <patrick at ianai.net>wrote:
>> Except the RIRs won't give you another /48 when you have only used
>> 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
> 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?
More information about the NANOG