ISP customer assignments - and CIDR

Fri Oct 16 21:44:59 UTC 2009

On Oct 16, 2009, at 5:19 PM, Owen DeLong wrote:

> I've taught both.  If you try to teach it in Decimal, Hex, or Octal,  
> you're right, it's hard
> to teach CIDR and easy to teach classful.

It really does not matter the representation as long as you divide  
your Address Pie with a Binary Knife.  Once you understand that --  
1/2, 1/2 of 1/2, 1/2 of 1/2 of 1/2, ... -- then you should understand  
CIDR.  Then, as Owen suggests, deal with the representation. Works for  
IPv4, IPv6, and, probably, IPv8. ;)

Warning, strong opinion follows: One should never have to mention  
Classful addressing except to note that it is archaic, anachronistic,  
and used only by those who remain ignorant by preference.

James R. Cutler
james.cutler at consultant.com