Re: [dhcwg] WGLC on draft-ietf-dhc-dhcpv6-privacy-01 - Respond by Sept. 22, 2015

[Marcin Siodelski <[e-mail]>]

I have read this document and I support advancing it. However, I found a
bunch of typos, which I am not listing here because it will be more
efficient if authors just run the spell check and easily locate them
themselves.

There are also some typos which wouldn't be picked by the spell checker
because they make existing words. However they cause various grammatical
and logical errors. It seems that authors may have neglected to do the
final proof reading of the whole text, because these errors are easy to
spot.

There are also additional issues which may, to some extent, overlap with
Jinmei's comments.

3. Identifiers in DHCPv6
Almost all sections belonging to section 3. (apart from the one
discussing DUID) describe *options* carrying some identifiers. So it
would be more appropriate to update the introductory text for section 3
to say:

"In DHCPv6, there are many options which include identification
information or can be used to extract the identification information
about the client. This section enumerates various options and
identifiers conveyed in them, which can be used to disclose client
identification."


and rename the section 3 to "DHCPv6 options carrying identifiers"

3.2. Client ID Option

The section title should be "Client Identifier Option" because this is
the actual name of this option.

What does it mean "Client ID is an example of DUID"? I thought that
"Client Identifier option is used to convey the DUID".

3.3. IA_NA, IA_TA... and co.

OLD:
"The IA Address option is used to specify IPv6 addresses ...."

NEW:
"The IA Address option is used to convey IPv6 addresses ..."

OLD:
" To differentiate between instances of the same type of IA containers,
   each IA_NA, IA_TA and IA_PD options have an IAID field that is unique
   for each client/option type pair. "

NEW:
" To differentiate between instances of the same type of IA containers
for a client, each IA option includes the IAID field with a unique value
for a given IA type".


3.8. Civic Location Option

OLD:
"DHCPv6 servers use the Civic Location option [RFC4776] to delivery of
   location information"

NEW:
"DHCPv6 servers use the Civic Location option [RFC4776] to deliver the
   location information.."

3.9. Coordinate based location

I don't know what this intends to say:
"After the relevant DHCPv6 exchanges have taken place, the location
   information is stored on the end device rather than somewhere else,
   where retrieving it might be difficult in practice."

- what is "end device"?
- what is "somewhere else" ?
- retrieving? You mean it is hard to breach privacy of the client using
this information because it is stored on the device running the DHCP client?

I think this section may try to convey a valid information but is
heavily unclear as stated.

3.10. Client System Architecture Type Option

"The Client System Architecture Type option [RFC5970] is used by
   DHCPv6 client to send a list of supported architecture types to the
   DHCPv6 server.  It is used to provide configuration information for a
   node that must be booted using the network rather than from local
   storage."

The part starting from

"It is used to provide configuration information..."

is wrong because the options providing configuration information for a
node (server to client) are different options, e.g. OPTION_BOOTFILE_URL.


I think I understand what you're trying to say, but you don't say what
you mean.

OLD:
"3.11.1. Subscriber ID"

NEW:
"3.11.1. Subscriber-ID Option"

OLD:
"3.11.2. Interface-ID"

NEW:
"3.11.2. Interface-ID Option"

OLD:
"3.11.3. Remote ID"

NEW:
"3.11.3. Remote-ID Option"

"4.  Existing Mechanisms That Affect Privacy
   This section describes available DHCPv6 mechanisms that one can use
   to protect or enhance one's privacy."

Is this really true? I thought the purpose of the document was to
describe the privacy issues related to the DHCPv6 protocol as it stands
with no attempt to provide any mitigation strategies.

If the purpose of the document is also to provide some recommendations
for the clients (or rather clients' implementors) to avoid some
operations leading to privacy breaching (without changing the protocol)
it should be clearly stated in the introduction. Currently the
introduction only states that this documents enumerates various
identifiers which can be used to obtain identification information about
the clients.

After reading section 4 I actually don't see any mitigation strategies
provided. So, the introductory text in  this section is wrong.

Marcin

On 02.09.2015 23:44, Bernie Volz (volz) wrote:
> Hi all,
> 
>  
> 
> This message starts the DHC Working Group Last Call to advance
> draft-ietf-dhc-dhcpv6-privacy-01, Privacy considerations for DHCPv6,
> http://tools.ietf.org/html/draft-ietf-dhc-dhcpv6-privacy-01. This
> document’s intended status is Informational. At present, there is no IPR
> file against this document.
> 
>  
> 
> This is a part of the WGLC of 3 documents
> (draft-ietf-dhc-dhcp-privacy-01,  draft-ietf-dhc-dhcpv6-privacy-01, and
> draft-ietf-dhc-anonymity-profile-03).
> 
>  
> 
> Please send your comments by September 22th, 2015. If you do not feel
> this  document should advance, please state your reasons why.
> 
>  
> 
> Bernie Volz is the assigned shepherd.
> 
>  
> 
> - Tomek & Bernie
> 
>  
> 
> 
> 
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