Re: [v6ops] A broken promise - "You said PD Prefix Valid Lifetime is going to be X" (Re: SLAAC renum: Problem Statement & Operational workarounds)

Ted Lemon <> Fri, 01 November 2019 13:33 UTC

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From: Ted Lemon <>
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Date: Fri, 1 Nov 2019 09:32:55 -0400
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To: "Bernie Volz (volz)" <>
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Subject: Re: [v6ops] A broken promise - "You said PD Prefix Valid Lifetime is going to be X" (Re: SLAAC renum: Problem Statement & Operational workarounds)
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On Nov 1, 2019, at 9:27 AM, Bernie Volz (volz) <> wrote:
> Both (until the old has expired).
> There might be a condition that on a Solicit we may not send the expiring one after the preferred lifetime has elapsed – but it was a while ago that this was implemented and need to check the details. If I recall correctly, I think was done because in the early days of DHCPv6 there were clients that would not handle multiple IAPREFIXes properly – for example, they would only use the first or fail. And, if done, that might hamper removal of the old prefix in devices behind the CPE as the CPE would not learn of this prefix on a power cycle.

Is it required that the CPE request both prefixes, or are they sent regardless?   Is the deprecated prefix sent with a preferred lifetime of zero?   I think this was the question we were discussing on the DHC mailing list yesterday, and I thought you said that this would be new behavior.  What am I missing?