if the ipv6 routing table ever gets as large as the ipv4 routing table is today (late 2004 if you're going to quote me later), we'll be in deep doo.
*WHEN* the ipv6 routing table gets as large as the ipv4 routing table is today (late 2004, when you quote me later) it won't be a problem.
As a matter of fact, I would bet that Cisco , Juniper, and any other edge/core router manufacturer are banking on this happening.
if it were just the routers, then you're apparently expecting the same owners to need better ones, and i agree that a router vendor would probably look very favourably on such a development. however, i'm counting on new owners needing their first routers, and an O(1e6) sized routing table doesn't make any difference there -- a router vendor might be even happier, in fact. but it's not just the routers, it's churn. "it's always noon somewhere." the stability of the distributed system called "the global routing table" is directly proportional to its size. the number of participants in that system, each of whom must build their own model of the system using only the messages they get from direct neighbors, cannot usefully exceed *some* maximum for any given total number of discrete destinations. if you think that the number of available participants leads to a maximum stable table containing O(1e6) destinations, then you should be arguing for a /20 minimum allocation size. If you think the table in question has O(1e10) destinations then you'd be arguing for a /30 minimum allocation size. But to consider a /40 minimum allocation size, you'd be saying that you thought a table containing O(1e12) discrete destinations, and i think that's false in two ways -- first, the current distance-vector approach used by BGP just won't scale to O(1e12), and second, i don't think that you think that there are enough participants who want to own routers to make such a table size necessary. someone asked about my "sole benefit" comment, so i'll amend it. it's not a global cost and sole benefit, but it is a global cost to the "other ends" with the preponderance of benefit (for a prefix) falling on the owner of the prefix. so it's not one-sided but it is certainly an assymetric benefit with a symmetric cost. mr. doran argued for many years that routing table slots should be auctioned or leased. i never did and still do not agree with him, but his starting assumptions weren't and aren't my point of disagreement. -- Paul Vixie