minimum IPv6 announcement size

Randy Carpenter rcarpen at
Fri Sep 27 17:04:23 UTC 2013

> There is no bit length which allocations of /20's and larger won't
> quickly exhaust. It's not about the number of bits, it's about how we
> choose to use them.
> Regards,
> Bill Herrin

True, but how many orgs do we expect to fall into that category? If the majority are getting /32, and only a handful are getting /24 or larger, can we assume that the average is going to be ~/28 ? If that is so, then out of the current /3, we can support over 30,000,000 entities. Actually, I would think the average is much closer to /32, since there are several orders of magnitude more orgs with /32 than /20 or smaller. Assuming /32 would be 500 million out of the /3. So somewhere between 30 and 500 million orgs.

How many ISPs do we expect to be able to support? Also, consider that there are 7 more /3s that could be allocated in the future.

As has been said, routing slots in the DFZ get to be problematic much sooner than address runout. Most current routers support ~1 million IPv6 routes. I think it would be reasonable to assume that that number could grow by an order of magnitude or 2, but I don't thin we'll see a billion or more routes in the lifetime of IPv6. Therefore, I don't see any reason to artificially inflate the routing table by conserving, and then making orgs come back for additional allocations.


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