Keith Moore <moore@xxxxxxxxxx> writes: > Sooner or later, routing scalability will be a problem in IPv6. When > that happens, each network will pick some means to decide which prefixes > get advertised within its network and which get filtered. It's not > rocket science to guess that networks will favor their own customers, > the networks with which they have explicit agreements, and the networks > from which their customers derive the most value. That probably puts > most ULAs and PIs fairly far down in the preference list. Actually, my read of arguments coming from those opposed to ULAs is that a good number of folk are worried that the some, if not many, ULAs would be pretty high up on the preference list. I.e., those hosting content that has become popular. And owners of those services will simply go to ISPs and say "route this, or I'll find someone else who will". And the sales and marketing departments of many ISPs will fall over each other to be the first to say "why certainly we'd love your business". And then the simple notion of filtering "all ULA space" goes out the window and we have huge mess, that involves even more pressures to accept more routes (despite the limitations on technology), etc. You may disagree with that scenario, but it is one that does concern people in the operational community and is one reason why the proposal is currently wedged. And when those making those arguments come from ISPs who have "been there and done that" and have been asked in previous lifetimes to do exactly that sort of thing, I gotta admit, it makes me a bit nervous. Thomas _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf