Subject: Re: Last Call on DHCP Options for SLP

From: Erik Guttman <[email-masked]>
Date: Thu, 28 Jan 1999 13:43:30 +0100

[email-masked] wrote:
> -------------------------------------------------------------------------------
> the SLP Service Scope Option still requires a one byte "mandatory" field
> within the option.  at the last ietf i thought we concocted a scheme where
> the mandatory field was not required.
> 

At the DHC meeting where SLP was discussed I believe we reached two 
conclusions:

  1. A Byte field is acceptable: It would not be hard to implement.

  2. Stating that the DHCP configured value MUST override static configuration
     for the value of scope is a bad idea.  But saying that static config
     overrides the DHCP option supplied value makes the option too weak for
     administrative control over SLP agent behavior.  Adding this control
     byte provides for either case at the discretion of the administrator.

The direction I came away with from the DHC meeting was that I should
remove the flag fields and instead include a byte field, and then to
reissue the internet draft.  

> my preference is that we define options using only the well defined set of
> types that have previously been used in option definition and not introduce
> a new encoding within an option. this option introduces a "structure"
> encoding within the option.

Another way to issue this draft would be to make it stronger and say that
the DHC SLP Scope option, if present, always overrides the user's static
configuration.

> if there is a strong requirement for this type of feature going forward,
> then i would like to see the dhcp advisory panel address this in a standard.
> by doing so, dhcp configuration systems can be built to allow for data
> driven configuration of new options.  the SLP Service Scope option requires
> that new option 79 specific code be added to our product (and likely a
> number of other vendors products).

If this is true, then we should probably go with the stricter interpretation
of the option: that it overrides static configuration.  In that case, the
"MANDATORY" byte is not required.

> in summary, generic new code is good.  specific to an option new code is
> bad. option 79 requires the latter. thus i am not in favour of this draft
> going forward in its current form.
> 
> /gww
> 
> > -----Original Message-----
> > From: [email-masked] [mailto:[email-masked]]On Behalf Of
> > Ralph Droms
> > Sent: Tuesday, January 26, 1999 16:06
> > To: Multiple recipients of list
> > Subject: Last Call on DHCP Options for SLP
> >
> >
> > This is a WG last call for comments on DHCP Options for SLP
> > <draft-ietf-dhc-slp-06.txt>.  Please respond to the [email-masked]
> > mailing list with comments by 3/5/99.  If there are no comments, the draft
> > will be submitted for acceptance as a Proposed Standard.
> >
> > - Ralph Droms
> >

Erik Guttman
Sun Labs