European ISP enables IPv6 for all?

Mikael Abrahamsson swmike at
Wed Dec 19 11:58:20 UTC 2007

On Wed, 19 Dec 2007, Iljitsch van Beijnum wrote:

> customers something bigger, like a /64, a /56 or even a /48. (Yes, we have 
> enough address space for a /48 per customer.)

The good part about using /48 is that it gives customers an even : boundry 
for their space. Apart from that, I think /56 is a better idea (or perhaps 
even a /60). Good point there about autoconfiguration, subnetting using 
less than /64 is probably a bad idea.

So, out of our /32, if we assign each customer a /48 we can only support 
65k customers. So in order to support millions of customers, we need a new 
allocation and I would really like for each new subnet allocated to be 
very much larger so we in the forseeable future don't need to get a newer 
one. So for larger ISPs with millions of customers, next step after /32 
should be /20 (or in that neighborhood). Does RIPE/ARIN policy conform to 
this, so we don't end up with ISPs themselves having tens of aggregates 
(we don't need to drive the default free FIB more than what's really 

Other option is to have more restrictive assignments to end users and 
therefore save on the /32, but that might be bad as well (long term).

Mikael Abrahamsson    email: swmike at

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