Re: [v6ops] A common problem with SLAAC in "renumbering" scenarios

[Fernando Gont <[e-mail]>]

On 26/2/19 07:06, Tim Chown wrote:
>> On 26 Feb 2019, at 09:33, Fernando Gont <[e-mail]> wrote:
>>
>> Section 6.2.1 of RFC 4861:
>>
>>      AdvPrefixList
>>                     A list of prefixes to be placed in Prefix
>>                     Information options in Router Advertisement
>>                     messages sent from the interface.
>>
>>                     Default: all prefixes that the router advertises
>>                     via routing protocols as being on-link for the
>>                     interface from which the advertisement is sent.
>>                     The link-local prefix SHOULD NOT be included in the
>>                     list of advertised prefixes.
>>
>>                     Each prefix has an associated:
>>
>>                        AdvValidLifetime
>>                             The value to be placed in the Valid
>>                             Lifetime in the Prefix Information option,
>>                             in seconds.  The designated value of all
>>                             1's (0xffffffff) represents infinity.
>>                             Implementations MAY allow AdvValidLifetime
>>                             to be specified in two ways:
>>
>>                               - a time that decrements in real time,
>>                                 that is, one that will result in a
>>                                 Lifetime of zero at the specified time
>>                                 in the future, or
>>
>>                               - a fixed time that stays the same in
>>                                 consecutive advertisements.
>>
>>                             Default: 2592000 seconds (30 days), fixed
>>                             (i.e., stays the same in consecutive
>>                             advertisements).
> 
> So given that document is 12 years old, with that default copied from one that is 21 years old, is an update required?  

That's my take.


> And if so, to what?

At the very least, never larger than the "Router Lifetime". Please see:
https://github.com/fgont/draft-slaac-renum/blob/master/draft-gont-6man-slaac-renum-02.txt
 (particularly Section 5.1.1)

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: [e-mail]
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