Re: Linux & draft-gont-6man-slaac-dns-config-issues

[Jen Linkova <[e-mail]>]

On Tue, Mar 24, 2015 at 5:22 PM, Fernando Gont <[e-mail]> wrote:
>> I agree that "<= 2x MaxRtrAdvInterval" limitation is way too strict
>> and we SHOULD fix this.
>> However I do not like the idea of sanitizing the received values and
>> limiting them to 10xMaxRtrAdvInterval.
>
> The thing here is that that's the only way (along with the change of the
> semantics of the Lifetime parameter) in which you can fix the problem on
> the client side.

Did I get it right that you are trying to solve one particular case
when people are shooting themselves in the foot?  I do not believe
that every single possible network misconfiguration case should be
solved on the client side, especially at the price of making life
harder for people who know what they are doing.

>> It really sounds like a
>> micromanaging network administrators in how they run their networks.
>> There might be valid reasons to have RDNSS/DNSSL Lifetime to be close
>> enough to how often RAs are sent (what if a router is a DNS server
>> itself? So if a router does down I don't want a client to use it).
>
> If that's de goal, then the Lifetime value should be set according to
> the "Valid Lifetime" of the RA, rather than according to MaxRtrAdvInterval

You mean Router Lifetime, don't you?
And yes, it might be equal to Router Lifetime, which might be
significantly lower than 6000 sec (1 hr 40 mins) you are proposing.

>> Actually, the wording of Sanitizing section is not accurate. Clients
>> do not know MaxRtrAdvInterval value as it's something configured on a
>> router. I assume it should be "the default MaxRtrAdvInterval value of
>> 600 sec"?
>
> Yes.

It would be nice to update the text accordingly.

-- 
SY, Jen Linkova aka Furry