Merge DHCPv4-over-DHCPv6 Enable and 4o6 Servers Option into one about ietf-dhc-relay-dhcp4-over-dhcp6

[msiodelski]

There is now one option 4o6 Server Address which may carry 0, 1 or more IP addresses. If the option is present, the DHCPv4 over DHCPv6 is enabled. If the option contains no addresses, the client sends to All_DHCP_Relay_Agents_and_Servers address. If the option is non-empty, the client sends request to all unique addresses from this option. The Enable option definition has been removed.

[frozensunq]

Hi Marcin,

Thanks for the efforts!

I have some comments on the wording.

1. The first 3 paragraphs of sec 6.2
   The current order is:
   a. The option contains multiple IPv6 addresses
   b. The option carries no address
   c. The presence / absence of the option

I'm thinking if it would be better if the order is changed a little:
a. Discuss the presence and absence of the option (absence also indicates to turn it off if it's already running)
b. zero address instructs using multicast
c. more addresses, send to all the all addresses

2. The current text states the option may be "empty", which word is not precise IMHO.
   How about using:
   the option length is zero.
   //I'm fine if the phrase "empty option" is well-known, just to make sure.

Please let me know if I missed anything.

Best Regards!
Qi

On 2013-12-14, at 上午3:16, msiodelski wrote:

There is now one option 4o6 Server Address which may carry 0, 1 or more IP addresses. If the option is present, the DHCPv4 over DHCPv6 is enabled. If the option contains no addresses, the client sends to All_DHCP_Relay_Agents_and_Servers address. If the option is non-empty, the client sends request to all unique addresses from this option. The Enable option definition has been removed.

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[msiodelski]

Qi,

On Tue, Dec 17, 2013 at 10:13 AM, frozensunq [email protected]:

Hi Marcin,

Thanks for the efforts!

I have some comments on the wording.

1. The first 3 paragraphs of sec 6.2
   The current order is:
   a. The option contains multiple IPv6 addresses
   b. The option carries no address
   c. The presence / absence of the option

I'm thinking if it would be better if the order is changed a little:
a. Discuss the presence and absence of the option (absence also indicates
to turn it off if it's already running)
b. zero address instructs using multicast
c. more addresses, send to all the all addresses

The section 6.2. describes the option format, not the client behavior. For
this reason I thought that the most important information is that this
option is devoted to carry IPv6 addresses the client should use - this is a
general case and a purpose of this option. Also, the first paragraph
describes the common part for this option format and other options sharing
this format.

The second paragraph describes an exception in the option format comparing
to other options holding a list of IPv6 addresses: it may contain no IPv6
addresses. IMHO, it is logical that the exception from the common format
appears after the format has been described in the first paragraph.

Finally, the 3 paragraph describes the client's behavior when it doesn't
get the option - but this is the least important part because it doesn't
really refer to the option format and the section is supposed to describe
the option format mainly :)

2. The current text states the option may be "empty", which word is not
   precise IMHO.
   How about using:
   the option length is zero.
   //I'm fine if the phrase "empty option" is well-known, just to make sure.

I looked into the latest version of the draft and I found two occurrences
of "empty":

1. " If the 4o6 Server Address option contains no addresses (is empty),"
2. " If the 4o6 client receives a 4o6 Server Address option that contains
   no IP addresses, i.e. the option is empty,"

In both cases it comes together with the explanation what the "emptiness"
means. So, I guess there is no problem.

Marcin