Re: [v6ops] Implementation Status of PREF64

"Dale W. Carder" <> Thu, 14 October 2021 13:58 UTC

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Date: Thu, 14 Oct 2021 08:58:19 -0500
From: "Dale W. Carder" <>
To: "Pascal Thubert (pthubert)" <>
Cc: Owen DeLong <>, "" <>
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References: <> <> <> <YWW1ghmjueHmfCEb@Space.Net> <> <YWW8FPkRuxCBFp3o@Space.Net> <> <YWcQKwK3lAKpl7y1@Space.Net> <> <>
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Subject: Re: [v6ops] Implementation Status of PREF64
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Thus spake Pascal Thubert (pthubert) ( on Wed, Oct 13, 2021 at 08:08:32PM +0000:
> Switching better than routing in the domain we call a subnet is also becoming obsolete since even when we think we switch we probably route at L2 or in an underlay.
> Bottom line is that /64 is still an interesting boundary for backward compatibility and old habits to form a group we call a subnet. But I agree with Gert that we do not need to give that much to every host just to be able to route inside the subnet at L2. 

It should not be lost that there are nice properties as well, for example 
the probability of duplicate address collision.  (See RFC4429 appendix A)