Re: draft-narten-ipv6-3177bis-48boundary-02.txt

["Jason Schiller (schiller@uu.net)" <jason.schiller@mci.com>]

On Thu, 13 Jul 2006, Iljitsch van Beijnum wrote:

> It 
> should be stressed that having different prefix sizes in the market  
> place leads to higher operational cost because moving from one ISP to  
> another then requires doing more work than just change a fixed number  
> of high bits in all places where addresses appear in configurations.
> 
> Obviously it's easier to renumber from a small prefix into a larger  
> one, but if different prefix sizes exist it can't be assumed that the  
> only movement is from service providers giving out long ones to  
> service providers giving out shorter ones.

If everyone accepts that ipv6 addresses have variable length subnet masks
(and everyone has the appropriate tools to handle this) and the RIRs have
a reasonably sound definition of what a good justification is for a given
size IP block, then I fail to see the value of "classful" addresses.

If a customer of ISP 1 adequately justified an ipv6 address with a
particular size mask, and then the customer decides to instead purchase
service from ISP 2, why wouldn't ISP 2 give out the same size ipv6 block?

Granted my two stipulations may create some initial pain, but we seemed to
manage it for IPv4, so I suspect we can do the same for ipv6.  There will
of course need to be some debate over the importance of aggregation
versus the importance of efficient use.  But we should be able to come up
with something reasonably balanced.  

___Jason