Re: Node Requirements: Elevating DHCPv6 from MAY to SHOULD

[Bob Hinden <[e-mail]>]

Timothy,

On May 13, 2011, at 9:28 AM, Timothy E. Enos wrote:

> Hi Thomas,
> 
> Thanks for posting this.
> 
> IMO, a SHOULD is not required in a SOHO environment (which is arguably not a corner case for deployment). MAY works.
> 
> Just as some environments may require the use of DHCPv6, some environments may not.
> 
> For those that require use of DHCPv6, they MAY use it.
> 
> I think at least in the SOHO context, it's really the local administrative policies (not hard and fast technical factors) that determine the (lack of) need for DHCPv6.
> 
> All the above said, my personal opinion is that DHCPv6 does not need to elevated to SHOULD from MAY for the node requirements spec. If the group decides to the contrary I can certainly accept that.

I think all we are trying to say that there are a wide range of deployment models, that we recommend that hosts SHOULD support both.  We are not making any statement about what should be used in a particular deployment.

Or at least, that's my thinking and why I support the SHOULD.  Also, why I suggested changing the text to not talk about "operators".

Bob



> 
> My $0.02,
> 
> Tim
> Ps 127:3-5
> 
> ----- Original Message ----- From: "Thomas Narten" <[e-mail]>
> To: <[e-mail]>
> Sent: Friday, May 13, 2011 9:37 AM
> Subject: Node Requirements: Elevating DHCPv6 from MAY to SHOULD
> 
> 
>> Per a previous thread, there are indications that the WG may now be
>> willing to recommend that DHCPv6 be a SHOULD for all hosts. This is
>> based on the following rationale:
>> 
>> Thomas Narten <[e-mail]> writes:
>> 
>>> I personally would support having DHCP be a SHOULD rather than a
>>> MAY. The justification in my mind is that if you want the network
>>> operator to have the choice of whether they want to use  Stateless
>>> addrconf OR DHCP, they only have that choice of devices widely
>>> implement both.
>> 
>> This was supported by some others, particularly now that it is clear
>> there are more implementations of DHCPv6, e.g.:
>> 
>> Bob Hinden <[e-mail]> writes:
>> 
>>> While my personal view is that DHCPv6 won't be used for host
>>> configuration in cable/DSL deployments (except for provisioning the
>>> prefix to the home router), it appears that DHCPv6 is being widely
>>> implemented in host OS's because it is needed some environments.
>>> There are enough variations in deployment models that a host
>>> developer will need to support both.
>> 
>>> Based on this, I think a SHOULD is OK.
>> 
>> Let me propose the following change be made to the node requirements
>> document:
>> 
>> OLD/Current:
>> 
>>  DHCP can be used to obtain and configure addresses.  In general, a
>>  network may provide for the configuration of addresses through Router
>>  Advertisements, DHCP or both.  At the present time, the configuration
>>  of addresses via stateless autoconfiguration is more widely
>>  implemented in hosts than address configuration via DHCP.  However,
>>  some environments may require the use of DHCP and may not support the
>>  configuration of addresses via RAs.  Implementations should be aware
>>  of what operating environment their devices will be deployed.  Hosts
>>  MAY implement address configuration via DHCP.
>> 
>> New:
>> 
>>     <t> DHCPv6 <xref target='RFC3315' /> can be used to obtain and
>> configure addresses. In general, a network may provide for the
>> configuration of addresses through Router Advertisements,
>> DHCPv6 or both.  Some operators have indicated that they do
>> not intend to support stateless address autoconfiguration on
>> their networks and will require all address assignments be
>> made through DHCPv6. On such networks, devices that support
>> only stateless address autoconfiguration will be unable to
>> automatically configure addresses. Consequently all hosts
>> SHOULD implement address configuration via DHCP.</t>
>> 
>> 
>> Is this acceptable?
>> 
>> Please respond yes or no. Given the WG's previous hesitation to having
>> DHCPv6 be a SHOULD, it is important that we get a clear indication of
>> whether or not the WG supports this change.
>> 
>> Thomas
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