I think ARIN is now doing sparse allocations on /28 boundaries. My personal opinion is that it should be even more sparse, and that allocations should be done on nibble boundaries. Any reasonably-sized ISP should get at least a /28. I deal with many small-ish ISPs, and most are 5,000-10,000 users. Those are probably served by a /32 for quite some time. When you get into the ones that are 20,000-50,000, it gets tricker to deal with. Those should get a /28. The mega-ISPs should get a /24, or even a /20. Another problem is that the allocations from IANA to the RIRs are too small to begin with. If there are 5 RIRs, why does there have to be so much fragmentation? It is too late for that, though. Anyway, I think there are some proposals floating around (Owen? ;-) ) That would make the /32,/28,/24 (nibble boundary) idea into policy. We'll have to wait and see what happens. -Randy -- | Randy Carpenter | Vice President, IT Services | Red Hat Certified Engineer | First Network Group, Inc. | (419)739-9240, x1 ---- ----- Original Message -----
On 26/10/2010 17:23, Owen DeLong wrote:
He's talking about the bloat that comes from ISPs getting slow-started and then only being able to increase their network in increments of 2x each time, so, effectively ISP gets: [...] Probably not quite as bad as IPv4, but, potentially close.
In theory, yes, it's bad.
In practice, the RIRs are implementing sparse allocation which makes it possible to aggregate subsequent allocations. I.e. not as bad as it may seem.
ARIN, RIPE and AfriNIC, for example, allocate on /29 boundaries. So if you get an initial allocation of /32, then find you need more, your subsequent allocations will be taken from the same /29, allowing aggregation up to /29.
APNIC seem to be delegating on /22 boundaries, and LACNIC on /28.
Nick