Mikael Abrahamsson swmike at
Fri Nov 29 05:25:21 UTC 2013

On Fri, 29 Nov 2013, Mark Andrews wrote:

> You can hand out /48 as easily with 6rd as you can natively.
> It's only when the ISP is lazy and encodes the entire IPv4 address
> space into 6rd thereby wasting most of the IPv6 address space being
> used for 6rd that a /60 appears to be generous.

You're contradicting yourself here. Yes, you're right about the technical 
solution, but it's not as easy (you need backend systems). Also, not all 
products support the variability of subnet lengths that the standard 

So if you're not mapping the entire space (actually some products only 
allow /32 IPv6 space) 1-1 you're making the whole solution harder due to 
complexity in your backend system plus you're limiting the amount of 
customer gear that will support the solution.

Mikael Abrahamsson    email: swmike at

More information about the NANOG mailing list