Re: [dhcwg] WGLC for draft-ietf-dhc-dhcpv4-over-dhcpv6-03 - Respond by Dec 9, 2013

Simon Perreault <simon.perreault@viagenie.ca> Wed, 27 November 2013 18:09 UTC

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Subject: Re: [dhcwg] WGLC for draft-ietf-dhc-dhcpv4-over-dhcpv6-03 - Respond by Dec 9, 2013
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Le 2013-11-27 11:18, Qi Sun a écrit :
>> - The client MUST always include both OPTION_DHCP4_O_DHCP6_ENABLE and
>> OPTION_DHCP4_O_DHCP6_SERVER in the ORO.
>>
>
> [Qi] RFC3315 says that the client SHOULD use unicast if instructed by
> the server. In this document, if the client doesn't include this option,
> it can still work (using multicast). So I think it's SHOULD for the
> OPTION_DHCP4_O_DHCP6_SERVER.

Let me repeat: You don't want to have a server sending an option that 
was not requested by the client. Stay with the usual ORO model.

Please explain why deviating from the usual ORO model is warranted.

>> - The server responds with zero (if DHCPv4-over-DHCPv6 is not
>> available) or one of two options. Never both.
>>    - OPTION_DHCP4_O_DHCP6_ENABLE means "multicast".
>>    - OPTION_DHCP4_O_DHCP6_SERVER means "unicast".
>>
>> If this makes sense, then I would rename the options:
>> s/ENABLE/MULTICAST/ and s/SERVER/UNICAST/. And maybe go further and
>> kill OPTION_DHCP4_O_DHCP6_ENABLE, and just put the multicast address
>> in the payload of OPTION_DHCP4_O_DHCP6_SERVER.
>
> [Qi] The multicast address is a well-known address in RFC3315. The
> client knows it even you don't tell the client. I don't think it
> necessary to put the multicast address into the option.

I did not argue that it was necessary to tell the multicast address to 
the client. I did argue that it was simpler to have only one option.

>> By the way, a suggestion for the document: replace all instances of
>> "4o6 Server Address option" with the full option name,
>> "OPTION_DHCP4_O_DHCP6_SERVER". Always using the same terminology makes
>> it much easier to grep the document.
>
> [Qi] Thanks for the suggestion! IMHO, the "4o6 Server Address option" is
> the name of the option, while the OPTION_DHCP4_O_DHCP6_SERVER is the
> option code to be assigned by the IANA. What I get from RFC3315 is that
> when you refer to an option, use the name; if you want to mention the
> code, then use the uppercase phrase.

Sure, it is common practice, but it still makes the document harder to 
grep. But this is just an editorial suggestion, I don't care much. Feel 
free to ignore it.

Simon
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