Subject: Re: Last Call: <draft-ietf-6man-stable-privacy-addresses-06.txt> (A method for Generating Stable Privacy-Enhanced Addresses with IPv6 Stateless Address Autoconfiguration (SLAAC)) to Proposed Standard

From: "Sujing Zhou"<[email-masked]>
Date: Thu, 2 May 2013 16:14:25 +0800

>> However, in the case of
>> roaming the feature is highly debatable. If a host visits the same
>> network multiple times, should it always reuse the same ID, or should
>> it get a new identifier each time? It is very easy to argue that
>> "different each time" has better privacy properties.

>Agreed. For instance, draft-ietf-6man-stable-privacy-addresses-06.txt is
>not a replacement for RFC4941. If you're a roaming node, you probably
>want RFC4941 enabled (in addition to having
>draft-ietf-6man-stable-privacy-addresses-06.txt enabled).

Have you ever considered add a date/time (optional ) parameter  in 
generation of the new RID,
for example:
 RID = F(Prefix, Interface_Index, Network_ID, DAD_Counter,Date/Time, 
secret_key),
thus will result in different IID each different year, each different 
month, or even 
different day.

Of course, the IID owner can choose to change secret_key  to obtain 
different IID,
but with an addition of date/time option, it is more flexible.

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From: Fernando Gont <[email-masked]>
Date: Thu, 02 May 2013 05:54:36 -0300

Hi, Sujing,

> but with an addition of date/time option, it is more flexible.

Not really. The addresses are meant to be constant. And if you want to
change them, it's better to update the secret key (updating the key is
usually good, and you get the address change you expected as a side effect).

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: [email-masked]
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492

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From: "Sujing Zhou"<[email-masked]>
Date: Fri, 3 May 2013 09:13:22 +0800

> usually good, and you get the address change you expected as a side 
effect).

Well，the owner may not want to update secret key just to change her/his 
ip with time passing, 
updating secret key frequently is bothersome.
An optional date/time can add more flexibility, if the owner wishes to 
obtain a constant IP, the date/time can be ignored,
if the owner wants to change IP once a year, the date/time can be chosen 
the year,......