ISP customer assignments

Ricky Beam jfbeam at
Tue Oct 6 03:23:17 UTC 2009

On Mon, 05 Oct 2009 20:14:01 -0400, Joe Greco <jgreco at> wrote:
> Generally speaking, we shouldn't *want* end users to be provided with a
> single /64.  The number of addresses is not the point.  The idea of
> getting rid of the horribleness that is CIDR is the point.

You underestimate the power of the marketing department and the bean  
counters.  I assure you, residential ISPs are looking for schemes to give  
out as little address space as possible.

> The current revision of IPv6 introduces a way to nail down the boundary
> between network and host.  This is fantastic, from an implementation
> point of view.  It simplifies the design of silicon for forwarding
> engines, etc.

And it's 150% Wrong Thinking(tm).  IPv6 is classless - PERIOD.  The  
instant some idiot wires /64 into silicon, we're right back to not being  
able to use x.x.x.0 and x.x.x.255.  Addresses are 128-bits; you cannot  
make any assumptions about what people may or may not be doing with those  
bits.  If I don't use SLAAC, then I'm not bound by it's lame rules.

> You don't do that.  Or at least, you shouldn't do that.  :-)  We have a
> fairly reliable DNS system these days...

And where did DNS get the name/number assignments?  In my case, it's  
either been typed in by ME or automatically updated by DHCP.


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