Re: SLAAC vs DHCPv6 (II)

[Fernando Gont <[e-mail]>]

On 28/1/20 00:56, Lorenzo Colitti wrote:
> On Tue, 28 Jan 2020, 11:25 Fernando Gont, <[e-mail] 
> <mailto:[e-mail]>> wrote:
> 
>      > Somebody tried to do this in DHC a few years ago, but it never
>     got much
>      > interest.
> 
>     Do address registration for SLAAC withing DHC WG?
> 
> 
> IIRC that was tried a few years ago and did not go anywhere (I think 
> Suresh has more details). >
> We could try again, though - if it's true that the main reason that 
> operators want DHCPv6 is tracking, then it could be a good middle ground 
> between devices that want SLAAC's ability to form addresses without 
> permission and networks that want DHCPv6's tracking abilities.

I don't believe the motivation is tracking, but some sort of control, 
including:
* logging
* "enforcing" policy on nodes



> If we do this it's important that the semantics only support tracking 
> existing addresses and not requesting addresses. Otherwise there will be 
> a conflict with the recommendations in RFC 7934 section 8 - and it would 
> basically be identical to IA_NA which is already a standard.

Well, the whole thread entitled "RFC4941bis: consequences of many 
addresses for the network" seem to be in conflict with RFC7934. -- i.e., 
folks have concerns about nodes configuring an arbitrary number of 
addresses at will.



> Note that 6man is working another way of getting this information to the 
> network, see the "multicast NA to ff02::2 whenever an address is 
> configured" proposal in draft-linkova-6man-grand.

I don't think that's registration in the same sense. For Jen's proposal, 
it's "best effort" registration. For logging, you need to implement a 
reliability mechanism. As we keep putting more state into SLAAC, it 
becomes more of AAC than SLAAC. And IPv6 automatic configuration as a 
whole becomes harder and harder to explain to newcomers, so to speak.

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