[address-policy-wg] an arithmetic lesson

Hello,

On 03.12.2009, at 13:08, Jim Reid wrote:

> On 3 Dec 2009, at 10:00, <michael.dillon at bt.com> wrote:
> 
>> an IPv6 /24 and an IPv4 /24 use up the same percentage of the total address space.
> 
> How do you work that out? Please enlighten me. 2^24/2^128 x 100 is many orders of magnitude smaller than 2^24/2^32 x 100:
> 	gromit% bc
> 	scale=50
> 	2^24/2^128*100
> 	.00000000000000000000000000000493038065763132378300
> 	2^24/2^32*100
> 	.39062500000000000000000000000000000000000000000000

Actually the size of a /24 is 2^(128-24) or 2^(32-24), sooo:

2^(32-24) / 2^32 * 100 = 1/2^24 * 100

and 

2^(128-24) / 2^128 * 100 = 1/2^24 * 100

Or am I missing something here: 

> There are of course the same number of IPv4 and IPv6 /24s.

If the Number of /24s is the same every one of them uses the same percentage of the Address-Space: 100 / (# of /24s)

lGuk
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Ulrich Kiermayr                       jabber xmpp:uk at jabber.univie.ac.at
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