Re: Last Call: <draft-ietf-6man-rfc4291bis-07.txt> (IP Version 6 Addressing Architecture) to Internet Standard Thu, 16 February 2017 21:24 UTC

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Subject: Re: Last Call: <draft-ietf-6man-rfc4291bis-07.txt> (IP Version 6 Addressing Architecture) to Internet Standard
Date: Thu, 16 Feb 2017 22:25:06 +0100
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> How do we move forward? What I think we need is to make it clear that there are real exceptions to 64, and it is therefore not acceptable to embed 64 in code.  The historic exception of addresses that start with 000 has been too amorphous, no one thinks it real. I've provided two exception that are clearly based on current standards track work, but I fear that still isn't enough.  I fear some will still embed 64 and just add code for the exceptions, if it's even really needed.
> Can you help me find something a little more?

I have run out of ideas. :-)

The challenge is to find text that enforces the 64-bit boundary policy (ignoring the technical arguments for a moment), and at the same time ensures implementors do the right thing and make their code handle any prefix length. Of course these are interdependent and doing the latter makes it harder to enforce the first.

> What about an additional exception for manual configuration?

It's an architecture document. It should draw the big lines.
I don't think it should list exceptions, perhaps not even the 6164 one.

Learn to live with it?

(And I promise not to mention host-routes aka addresses with a /128 and interface-id length of 0.) :-)

Best regards,