Realistic number of hosts for a /64 subnet?

Gert Doering gert at
Fri May 10 13:10:20 CEST 2019


On Fri, May 10, 2019 at 01:07:44PM +0200, H.Zuleger wrote:
> > (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)
> Maybe, but this large address space, give you the room for all these ideas (and a lot more like 8+8 etc.).
> I think the great benefit and the main driver was (and is) the full automated address configuration.

I've heard lots of "great ideas" in the last 20 years...

What is left:

 - large networks are hard
 - can we please do p2p instead, routed, wherever possible
 - autoconfig based on hardware identifiers sucks, can we please do
   something hash-based (= autoconf in a /96 would quite likely work
   perfectly fine)

 - we do not have enough bits *in front* of the /64 mark to do nice things

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

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