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

[Fernando Gont <[e-mail]>]

Hi, Jen,

On 03/24/2015 09:20 AM, Jen Linkova wrote:
> On Tue, Mar 24, 2015 at 2:26 PM, Lorenzo Colitti <[e-mail]> wrote:
>> To clarify: I mean that we should just strike the text that specifies that
>> the maximum duration SHOULD be <= 2x the router advertisement interval. That
>> doesn't make sense to me.
> 
> +1
> 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.



> 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


> BTW it is also a reason I'm concerned about changing the Lifetime
> field semantic.
> 
> 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.

Thanks!

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