Re: RFC 5006 status

[Syam Madanapalli <smadanapalli@gmail.com>]

On Fri, Mar 19, 2010 at 7:24 PM, Rémi Després <remi.despres@free.fr> wrote:
>
> Le 19 mars 2010 à 12:05, Syam Madanapalli a écrit :
>
>> What's the difference between running Stateless DHCPv6 vs carrying
>> DHCP options in ND messages?
>
> As noted by Ralph (who was not arguing in favor of RAs, but just stating a fact):
> "There is one way in which RAs involve less overhead - they can use multicast to carry all the options in one message rather than use individual message exchanges for each host."
>
> Other differences can be discussed, but there is at least this one.
>
>> If nodes can implement DHCP options in ND messages, I could not
>> understand why cannot they implement Stateless DHCPv6 itself.
>
> This question amounts to:
> "why to make it simpler when you can afford to keep it complex?"

Sure, as far as I know that's how things being done at the IETF - If
it ain't broke, don't fix it.

> The right answer is IMHO in the sentence of Saint-Exupery quoted by Mark Smith on this thread:
> "In anything at all, perfection is finally attained not when there is no longer anything to add, but when
> there is no longer anything to take away."
>
>> DHCPv6, then we need to look at whether there exists any other options
>> other the DNS server address for which IETF is looking at defining RA
>> options.
>
> No.
> Not more than to specify Stateless DHCP servers.
> (Note incidentally that RFC on Stateless DHCPv6 (RFC 3736) already mentions SIP-server addresses as useful stateless parameters, without this closing the list for the future.)
>
> The standard needs only to say that:
> - Routers MAY send RAs containing stateless DNS options
> - Hosts MAY be ready to receive stateless DNS options in RAs
> - IF THEY DO, it MUST be with the approved format.
> (And, for this, the format proposed by Suresh is so obvious and simple that I doubt there would be any competitive proposals)
>
> This being done, one can expect that all vendors of products that send and/or receive RAs will eventually add this simple capability to their products, making things more efficient and simpler in many circumstances.

I doubt this. For me this would be a new standard that needs to be
implemented new.

And if you are proposing the RA DHCP option for DNS server address
alone, for the argument sake, this involves one extra step in
processing than RFC 5006.

I hope there will not be another proposal for RA into DHCP :-)

Thanks,
Syam

>
> Regards,
> RD
>
>
>>
>> Thanks,
>> Syam
>>
>> On Fri, Mar 19, 2010 at 3:29 PM, Rémi Després <remi.despres@free.fr> wrote:
>>>
>>> Le 17 mars 2010 à 16:18, Fred Baker a écrit :
>>>
>>>> http://www.ietf.org/rfc/rfc5006.txt
>>>>
>>>> (1) Please take a look at the document in the next few days; if you have comments on it (eg, you think it should be changed in some way), please comment to v6ops.
>>>
>>> While supporting in general the idea, there is one improvement I suggest to make:
>>> Rather than a specific RA option for Recursive DNS Servers, standardize the generic RA option to embed some stateless DHCP options, as proposed in draft-krishnan-intarea-ra-dhcp-00.
>>>
>>> This is in my understanding more powerful without being more complex.
>>> By giving to routers a general possibility to broadcast stateless DHCP parameters (in addition to their still being obtainable in DHCPv6), not only the purpose of RFC50026 is achieved but, in one shot, the same progress is made for all common parameters that may concern all or most hosts.
>>>
>>> Hosts that support the RA DHCP option only have to: (1) process embedded DHCP options that they understand; (2) skip others; (3) request in DHCPv6 only options that aren't already received in RAs, if any.
>>>
>>> Note that Suresh Krishnan has 15min slot scheduled at the 6man meeting of Wednesday for:
>>> "Stateless DHCPv6 and Router Advertisements for propagating configuration information".
>>>
>>> I add Suresh to the list, and Dan Wing who is known to support this approach.
>>>
>>> RD
>>>
>>>
>
>