[dhcwg] Re: [Technical Errata Reported] RFC9686 (8600 )

Warren Kumari <[email protected]> Tue, 14 Oct 2025 13:01:56 -0700
Newsgroups gmane.ietf.dhc
Message-ID <CAHw9_i+6bYeVv8LV-Q_42sKiqf+UUYxjkivciO-oSEsw1m1KyQ@mail.gmail.com>
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I believe that this errata should be rejected, or  hold for document update=
.

"Errata are meant to fix "bugs" in the specification and should not be used
to change what the community meant when it approved the RFC." -
https://datatracker.ietf.org/doc/statement-iesg-iesg-processing-of-rfc-erra=
ta-for-the-ietf-stream-20210507/

While this text could *clearly* be improved, this was the consensus when
the document was published, so this isn't really an Errata.


IIRC, we did have some discussions around "1% or <some time>, whichever is
greater" but we were not able to get any sort of consensus on <some time>,
and so the consensus was to go with this=E2=80=A6

W



On Tue, Oct 14, 2025 at 2:22 PM, RFC Errata System <
[email protected]> wrote:

> The following errata report has been submitted for RFC9686,
> "Registering Self-Generated IPv6 Addresses Using DHCPv6".
>
> --------------------------------------
> You may review the report below and at:
> https://www.rfc-editor.org/errata/eid8600
>
> --------------------------------------
> Type: Technical
> Reported by: Patrick Rohr <[email protected]>
>
> Section: 4.6.1
>
> Original Text
> -------------
> Whenever the network changes the Valid Lifetime of an existing address by
> more than 1%, for example, by sending a Prefix Information Option (PIO)
> [RFC4861] with a new Valid Lifetime, the client calculates a new
> AddrRegRefreshInterval.
>
> ---
>
> * The 1% tolerance ensures that the client will not refresh or reschedule
> refreshes if the Valid Lifetime experiences minor changes due to
> transmission delays or clock skew between the client and the router(s)
> sending the RA.
>
> Corrected Text
> --------------
> Whenever the network changes the Valid Lifetime of an existing address by
> more than 3s, for example, by sending a Prefix Information Option (PIO)
> [RFC4861] with a new Valid Lifetime, the client calculates a new
> AddrRegRefreshInterval.
>
> ---
>
> * The 3s tolerance ensures that the client will not refresh or reschedule
> refreshes if the Valid Lifetime experiences minor changes due to
> transmission delays or clock skew between the client and the router(s)
> sending the RA.
>
> Notes
> -----
> Replace 1% tolerance with 3s tolerance.
>
> Rationale: As the remaining lifetime approaches zero, the 1% tolerance
> also approaches zero which can trigger redundant address refreshes. This
> problem is exacerbated by potential integer rounding, where 1% of 99s cou=
ld
> be rounded down to 0s. Android's implementation of this mechanism uses a =
3s
> tolerance instead. Since both clock skew and transmission delays are
> independent from the address lifetime, using a static tolerance is more
> consistent and still follows the original intent of this mechanism.
>
> Instructions:
> -------------
> This erratum is currently posted as "Reported". (If it is spam, it will b=
e
> removed shortly by the RFC Production Center.) Please use "Reply All" to
> discuss whether it should be verified or rejected. When a decision is
> reached, the verifying party will log in to change the status and edit th=
e
> report, if necessary.
>
> --------------------------------------
> RFC9686 (draft-ietf-dhc-addr-notification-13)
> --------------------------------------
> Title : Registering Self-Generated IPv6 Addresses Using DHCPv6 Publicatio=
n
> Date : December 2024
> Author(s) : W. Kumari, S. Krishnan, R. Asati, L. Colitti, J. Linkova, S.
> Jiang Category : PROPOSED STANDARD
> Source : Dynamic Host Configuration
> Stream : IETF
> Verifying Party : IESG
>
>

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<html><head></head><body><div><div><div class=3D""><div class=3D""><div cla=
ss=3D""><div class=3D"">I believe=C2=A0that this errata should be rejected,=
 or=C2=A0=C2=A0hold for document update.<br></div><div class=3D""><br></div=
><div class=3D"">&quot;Errata are meant to fix &quot;bugs&quot; in the spec=
ification and should not be used to change what the community meant when it=
 approved the RFC.&quot; -=C2=A0<a href=3D"https://datatracker.ietf.org/doc=
/statement-iesg-iesg-processing-of-rfc-errata-for-the-ietf-stream-20210507/=
" class=3D"">https://datatracker.ietf.org/doc/statement-iesg-iesg-processin=
g-of-rfc-errata-for-the-ietf-stream-20210507/</a><br></div><div class=3D"">=
<br></div></div></div></div><div class=3D"">While this text could *clearly*=
 be improved, this was the <span class=3D"">consensus</span>=C2=A0when the =
document was published, so this isn&#39;t really an Errata.<br></div><div c=
lass=3D""><div class=3D""><div class=3D""><div class=3D""><br></div><div cl=
ass=3D""><br></div><div class=3D"">IIRC, we did have some discussions aroun=
d=C2=A0&quot;1% or &lt;some time&gt;, whichever is greater&quot; but we wer=
e not able=C2=A0to get any sort of consensus=C2=A0on &lt;some time&gt;, and=
 so the consensus=C2=A0was to go with this=E2=80=A6<br></div><div class=3D"=
"><br></div><div class=3D"">W<br></div><div class=3D""><br></div></div><div=
 class=3D"sh-signature"><div class=3D"gmail_signature"><br></div></div></di=
v><div class=3D""><br></div><div class=3D"sh-quoted-content"><div class=3D"=
"><div class=3D"gmail_quote"><div class=3D"">On Tue, Oct 14, 2025 at 2:22 P=
M, RFC Errata System <span class=3D"" dir=3D"ltr">&lt;<a class=3D"" href=3D=
"mailto:[email protected]">[email protected]</a>&gt;</span>=
 wrote:<br></div><blockquote style=3D"margin:0 0 0 .8ex;border-left:1px #cc=
c solid;padding-left:1ex" class=3D"gmail_quote"><div class=3D"gmail_extra">=
<div class=3D"gmail_quote"><p class=3D""></p><div class=3D"">The following =
errata report has been submitted for RFC9686, <br></div><div class=3D""> &q=
uot;Registering Self-Generated IPv6 Addresses Using DHCPv6&quot;.<br></div>=
<p></p><p class=3D""></p><div class=3D"">----------------------------------=
---- <br></div><div class=3D""> You may review the report below and at: <br=
></div><div class=3D""> <a class=3D"" href=3D"https://www.rfc-editor.org/er=
rata/eid8600" rel=3D"noopener noreferrer">https:/<wbr>/<wbr>www.<wbr>rfc-ed=
itor.<wbr>org/<wbr>errata/<wbr>eid8600</a><br></div><p></p><p class=3D""></=
p><div class=3D"">-------------------------------------- <br></div><div cla=
ss=3D""> Type: Technical <br></div><div class=3D""> Reported by: Patrick Ro=
hr &lt;<a class=3D"" href=3D"mailto:[email protected]" rel=3D"noopener noref=
errer">prohr@<wbr>google.<wbr>com</a>&gt;<br></div><p></p><p class=3D"">Sec=
tion: 4.6.1 <br></p><p class=3D""></p><div class=3D"">Original Text <br></d=
iv><div class=3D""> ------------- <br></div><div class=3D""> Whenever the n=
etwork changes the Valid Lifetime of an existing
address by more than 1%, for example, by sending a Prefix Information
Option (PIO) [RFC4861] with a new Valid Lifetime, the client
calculates a new AddrRegRefreshInterval.<br></div><p></p><p class=3D"">--- =
<br></p><p class=3D"">*  The 1% tolerance ensures that the client will not =
refresh or
reschedule refreshes if the Valid Lifetime experiences minor
changes due to transmission delays or clock skew between the
client and the router(s) sending the RA. <br></p><p class=3D""></p><div cla=
ss=3D"">Corrected Text <br></div><div class=3D""> -------------- <br></div>=
<div class=3D""> Whenever the network changes the Valid Lifetime of an exis=
ting
address by more than 3s, for example, by sending a Prefix Information
Option (PIO) [RFC4861] with a new Valid Lifetime, the client
calculates a new AddrRegRefreshInterval.<br></div><p></p><p class=3D"">--- =
<br></p><p class=3D"">*  The 3s tolerance ensures that the client will not =
refresh or
reschedule refreshes if the Valid Lifetime experiences minor
changes due to transmission delays or clock skew between the
client and the router(s) sending the RA. <br></p><p class=3D""></p><div cla=
ss=3D"">Notes <br></div><div class=3D""> ----- <br></div><div class=3D""> R=
eplace 1% tolerance with 3s tolerance.<br></div><p></p><p class=3D"">Ration=
ale: As the remaining lifetime approaches zero, the 1% tolerance also appro=
aches zero which can trigger redundant address refreshes. This problem is e=
xacerbated by potential integer rounding, where 1% of 99s could be rounded =
down to 0s.
Android&#39;s implementation of this mechanism uses a 3s tolerance instead.=
 Since both clock skew and transmission delays are independent from the add=
ress lifetime, using a static tolerance is more consistent and still follow=
s the original intent of this mechanism. <br></p><p class=3D""></p><div cla=
ss=3D"">Instructions: <br></div><div class=3D""> ------------- <br></div><d=
iv class=3D""> This erratum is currently posted as &quot;Reported&quot;. (I=
f it is spam, it=20
will be removed shortly by the RFC Production Center.) Please
use &quot;Reply All&quot; to discuss whether it should be verified or
rejected. When a decision is reached, the verifying party =20
will log in to change the status and edit the report, if necessary.<br></di=
v><p></p><p class=3D""></p><div class=3D"">--------------------------------=
------ <br></div><div class=3D""> RFC9686 (draft-ietf-dhc-addr-notification=
-13) <br></div><div class=3D""> -------------------------------------- <br>=
</div><div class=3D""> Title               : Registering Self-Generated IPv=
6 Addresses Using DHCPv6
Publication Date    : December 2024 <br></div><div class=3D""> Author(s)   =
        : W. Kumari, S. Krishnan, R. Asati, L. Colitti, J. Linkova, S. Jian=
g
Category            : PROPOSED STANDARD <br></div><div class=3D""> Source  =
            : Dynamic Host Configuration <br></div><div class=3D""> Stream =
             : IETF <br></div><div class=3D""> Verifying Party     : IESG<b=
r></div><p></p></div></div></blockquote></div></div></div></div><div class=
=3D""><br></div></div><div></div></div></body></html>

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