On 22-mei-2007, at 3:00, Fred Baker wrote:
The third is why this needs to be a managed space per se. If the desire is for a space that can be used within an ISP network and is guaranteed to not overlap that of any routing peer, placing the 32 bit AS number into the upper bits of the "Global ID" gives each provider a /40 to play with, with no effort on the IANA's part. Why not just do so?
this seems like the most reasonable way of distributing ULA that i've read. apologies if that idea has been around for a while and i'm only now just hearing it.
I have no idea if anyone else is discussing it either. I just work here... :-)
Go talk to a multi6 survivor...The problem is that one size never fits all so many ASes will get such a block and never use it, and since this is supposed to be private space, many people who want it won't have an AS number. Not a good idea, IMO.
The problem is that the randomly generated ULA blocks still hold the potential for clashes upon mergers, and people are bitten by that with RFC 1918 space so they're not prepared to take a one-in-2^40 risk. Or more likely, the risk that the randomization rules aren't followed properly. Another advantage of ULA-c is that it's possible to get the reverse DNS delegated, which can be helpful.
So why don't we implement a way for people to get centrally assigned ULAs? The simple way to do this is to sell prefixes of a suitable size (I'm thinking 20 bits worth) to people who are prepared to run a registry for further distribution. In practice, this means that pretty much everyone who sells domains will be selling ULA-cs, too. Simple, easy.