[address-policy-wg] RE: an arithmetic lesson

/24 is ~0.000006% of whole ipv4 space (256 / 4294967296)
/24 is ~0.000006% of whole ipv6 space (2^104 / 2^128)


Regards
Martin Hindley



-----Original Message-----
From: address-policy-wg-admin at ripe.net [mailto:address-policy-wg-admin at ripe.net] On Behalf Of michael.dillon at bt.com
Sent: 03 December 2009 13:20
To: address-policy-wg at ripe.net
Subject: RE: [address-policy-wg] RE: an arithmetic lesson



> As I understand:
> Or not ?

I don't know. The simple fact is that a /24
block is the set of addresses that use the
same prefix which is defined by a 24-bit
netmask. That means, that all of the addresses
in the block will have the same pattern
in the first 24 bits.

Asking how many /24 blocks can be carved out
of the total numberspace is equivalent to
asking how many unique patterns there are
of 24 binary digits. It should be obvious
that the number of unique patterns of 24
binary digits is the same regardless of
whether you use the first 24 bits out of
a total of 32, or the first 24 bits out of
a total of 128.

One single /24 block is the same percentage
of the total numberspace regardless of whether
the protocol is v4 or v6.

--Michael Dillon