Re: [v6ops] Implementation Status of PREF64

Ole Troan <> Thu, 14 October 2021 19:07 UTC

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From: Ole Troan <>
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Date: Thu, 14 Oct 2021 21:07:46 +0200
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Cc: "Pascal Thubert (pthubert)" <>,, Owen DeLong <>
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To: Ted Lemon <>
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Subject: Re: [v6ops] Implementation Status of PREF64
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> On 14 Oct 2021, at 19:11, Ted Lemon <> wrote:
>> On Thu, Oct 14, 2021 at 2:56 AM Pascal Thubert (pthubert) <> wrote:
>> A prefix to the host gives Lorenzo the addresses he needs for his devices.  It gives your customers the single state per logical node that they want. It allows to separate what netops manage (down to /64 and direct assignment within) and devops (whatever they do with the longer prefix they get for their node). It does not impose any size for what’s assigned, could be a different thing for each host. It means routing inside the subnet which removes the dreadful broadcast domain.
>> I see an opportunity for consensus. Can we work that out together and bring a real IPv6 value?
> If your proposal is that we use a /64 per host as a way to meet these needs, I agree. This solves everybody's actual problems. There is the issue that some people have expressed a preference for prefixes wider than 64 bits, but this is a preference—there's no technical reason to do this. It's not wrong to have preferences, but it would be nice if we could somehow finally put this discussion to bed.

Limiting networks that are assigned a /56 to only 256 logical nodes is a non starter.