[arin-ppml] Rationale for /22

Ted Mittelstaedt tedm at ipinc.net
Thu Jul 30 15:56:15 EDT 2009

Jon Lewis wrote:
> On Thu, 30 Jul 2009 bmanning at vacation.karoshi.com wrote:
>> On Thu, Jul 30, 2009 at 01:56:43PM -0400, Leo Bicknell wrote:
>>> In a message written on Thu, Jul 30, 2009 at 12:19:19PM -0500, 
>>> George, Wes E [NTK] wrote:
>>>> To the question of "existing filters/inertia aside, is there a
>>>> justification for *any* minimum allocation size?"
>>> While it is a bit of a reductio ad absurdum argument, consider what
>>> (could) happen if the minimum were a /32.
>>     kind of like what happens when we give out everyone a /32
>>     of IPv6 space.  your arguments are identical for either
>>     an IPv4 or IPv6 /32.
>>     and yet we find it acceptable to hand out /32's in one space...
> The difference being, v6 is so much bigger than v4 

With IPv6 the host identifer portion of the address is 64 bits to
allow stateless autoconfiguration - essentially, using the MAC
address as the host ID.  THAT is why each subnet is so large.

It's a clever way to simplify and
get rid of DHCP servers and makes a huge amount of sense in some

Take a look at the following:


As Chris says in the first link:

"...So, while there may be well over an octillion times more individual 
IPv6 addresses than there are IPv4 addresses; in terms of actual 
usability, IPv6 is only somewhere in the range of 16 million to 17 
billion times larger than IPv4.  Much larger, yes; infinite, no...."


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