Re: [dhcwg] [radext] draft-ietf-dhc-dhcpv6-radius-opt-10

On Apr 5, 2013, at 12:04 AM, Ted Lemon <Ted.Lemon@nominum.com> wrote:

> On Apr 4, 2013, at 4:57 PM, Alan DeKok <aland@deployingradius.com> wrote:
>> Positive statements are usually clearer to understand.
> 
> Yes, and when I read your statement, I understood it to mean the exact opposite of what you intended.   Easier to understand doesn't help if the statement is ambiguous.
> 
>> The intention is for the option to carry RADIUS attributes.  Making
>> that a requirement rather than a suggestion is a good idea.
> 
> This isn't what the text says.   It says that the option must only carry a subset of RADIUS attributes; those listed in a special registry.
> 
> If you don't like the double negative, here's a precise way to say it that doesn't contain a double negative:
> 
> 	This option MUST NOT carry any RADIUS attribute unless it is listed in the
> 	IANA Registry of 'RADIUS attributes permitted in DHCPv6 RADIUS option'.

I don't think this is any improvement over the text Alan provided originally.
My suggestion would be:

   The option-data of OPTION_RADIUS is a list of one or more RADIUS
   attributes received in the Access-Accept message from the RADIUS
   server. The OPTION_RADIUS can only contain RADIUS attributes
   listed in the IANA Registry of 'RADIUS attributes permitted in
   DHCPv6 RADIUS option'.

The next question I have is what happens when a relay includes an attribute
that the server does not understand or is not listed in the registry? There
is no versioning thus it is possible that relay and server have a different
understanding what the IANA registry is. Now the text in Section 6 only
addresses the case where the server does not understand the DHCP option.

- Jouni

> 
> But what the text that means what you said in the second quote above would read like this:
> 
> 	This option MUST NOT carry any RADIUS attribute unless it is listed in the
> 	IANA Registry Radius Types registry in the section titled 'Radius Attribute Types'.

> 
> _______________________________________________
> dhcwg mailing list
> dhcwg@ietf.org
> https://www.ietf.org/mailman/listinfo/dhcwg