In message <alpine.DEB.2.02.1311290622170.1157@uplift.swm.pp.se>, Mikael Abrahamsson writes:
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.
What contradiction? You need to break up the IPv6 address allocation for both PD and 6rd. I would say PD is slightly more complicated than 6rd as you also want to optimise routing more with PD. With 6rd you do the optimisation using the IPv4 addresses.
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 allows.
So who is shipping cr*p that claims to support RFC 5969 yet doesn't all arbitary size 6rd domains? The point of have a standard is so equipement from different manufactures can work together. A CPE device that can't accept all legal values should be thrown in the bin.
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.
I claim bovine excrement on customer gear. Show me where the 6rdPrefixLen is defined to be 32? Even with RFC 5569 it was up to 32 and the IPv4MaskLen is 0.
-- Mikael Abrahamsson email: swmike@swm.pp.se -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org