Too-frequent change of privacy address / ND monitoring

[Marco Sommani]

On 27/mar/2013, at 08:31, Fernando Gont <fernando at gont.com.ar> wrote:

> On 03/26/2013 09:29 AM, Marco Sommani wrote:
>> Phil,
>> 
>> when everything works according to standards, temporary addresses are
>> regenerated just before the preferred lifetime times out, so you have
>> the possibility to alter the frequency of renewals by changing the
>> preferred-lifetime of the prefix in the Router-Advertisements.
> 
> Privacy addresses will very likely regenerate before such timer expires.
> -- Actually, such timer shouldn't expire if you continue receiving RAs...
> 
> Cheers,
> -- 
> Fernando Gont

Well, I must admit that you are right. The correct behaviour is described in section 3.3 of RFC 4941:

>    1.  Process the Prefix Information Option as defined in [ADDRCONF],
>        either creating a new public address or adjusting the lifetimes
>        of existing addresses, both public and temporary.  If a received
>        option will extend the lifetime of a public address, the
>        lifetimes of temporary addresses should be extended, subject to
>        the overall constraint that no temporary addresses should ever
>        remain "valid" or "preferred" for a time longer than
>        (TEMP_VALID_LIFETIME) or (TEMP_PREFERRED_LIFETIME -
>        DESYNC_FACTOR), respectively.  The configuration variables
>        TEMP_VALID_LIFETIME and TEMP_PREFERRED_LIFETIME correspond to
>        approximate target lifetimes for temporary addresses.

So, there is no way to influence the frequency of regeneration of temporary addresses from Router Advertisements.

-- 
Marco Sommani
Consiglio Nazionale delle Ricerche
Istituto di Informatica e Telematica
Via Giuseppe Moruzzi 1
56124 Pisa - Italia
work: +390506212127 (PSTN and nrenum.net)
mobile: +393487981019
fax: +390503158327
mailto:marco.sommani at cnr.it