Realistic number of hosts for a /64 subnet?

Gert Doering gert at
Fri May 10 12:21:05 CEST 2019


On Fri, May 10, 2019 at 08:26:46AM +0200, Mark Tinka wrote:
> Whether a single LAN can scale to the number of devices a /64 can
> maximally support... I don't think so, but I also don't know of anyone
> who has tried.

Math says there is no way to do that.   Like, store 2^63 ND entries
in finite memory...

(The whole reason why /64 semeed a good idea back then was CGA and
"we can make it work with EUI-64 on IEEE-1394 devices!", of which CGA
never truly happened, EUI-64 based on MAC addresses is dying off, and
IEEE-1394 is long gone...  I always thought that /64 was a bit silly)

Gert Doering
        -- NetMaster
have you enabled IPv6 on something today...?

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