Re: New Version Notification for draft-hinden-ipv4flag-00.txt

Bob Hinden <> Fri, 17 November 2017 23:32 UTC

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From: Bob Hinden <>
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Subject: Re: New Version Notification for draft-hinden-ipv4flag-00.txt
Date: Sat, 18 Nov 2017 07:31:58 +0800
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Cc: Bob Hinden <>, Fernando Gont <>, IPv6 List <>
To: james woodyatt <>
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Cutting to the end:

> On Nov 18, 2017, at 2:39 AM, james woodyatt <> wrote:
> On Nov 17, 2017, at 00:17, Bob Hinden <> wrote:
>> The flag is to tell the host to not use IPv4.  Once the host see the Flag=1, it should stop sending IPv4.
> The draft is very confused about what the flag means. And both of the conflicting descriptions in the draft are in conflict with this statement. Here are the three conflicting positions (I’m wondering how many will emerge before this can be sent back to the April 1 queue).
>  — "IPv4 is Not Available on this Router"
>  — "A host that receives only RAs with the flag set to 1 should not attempt IPv4 operations, unless it subsequently receives at least one RA with the flag set to zero."
>  — "A host that receives Flag=1 should stop sending IPv4" (to what routers? on which interfaces? until what condition arises?).
> Please send this draft back into the For Comedy Purposes Only category and leave the serious business of this topic to the SUNSET4 working group, which is actually chartered to deal with it.

That’s harsh.

I note that the relevant draft in sunset4 has been updated in 3 years, and Sunset four hasn’t meet since IETF97.  Doesn’t seem like anything will happen there.

We wrote this to solve what I think is a real issue observed with the use of NAT64 on the IETF100 network.


> --james woodyatt <>