Where to buy Internet IP addresses

Carsten Bormann cabo at tzi.org
Wed May 6 00:12:42 CDT 2009

> Sure, but how does the router know it needs to hand out a /62? Then  
> what about the router after that? Does it hand out a /61? then the  
> router behind that?

For now: Reserve a /64 for your own allocations (SAA), then hand out  
half of what you have (i.e., of a /56 for the first CPE, so a /57) to  
the first asker, then a /58, then a /59 etc.  The first asker (nested  
CPE) has a /57, reserves a /64 for itself (SAA), hands out a /58 to  
its first child (double-nested CPE), then a /59.
This algorithm restricts width plus depth to 8 (64 - 56), which is  
probably fine for most residential applications.

The probabilistic aspect (FCFS) may cause you cognitive dissonance,  
but little technical problem.
(Something that could be said about many of the "I grew up on IPv4 so  
I don't understand IPv6" postings here.)

> What if the ISP only gave a /60?

Don't do that then!

Really, /56 for everyone is the only way back to an Internet.

Gruesse, Carsten

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