Re: [DNA] Last call: Detection of Network Attachment (DNA) in IPv4(fwd)

[JinHyeock Choi <jinchoe@gmail.com>]

Bernard 

> > 1. Abbreviation
> > For IPv4, DNA stands for "Detection of Network Attachment", whereas
> > for IPv6, DNA stands for "Detecting Network Attachment".
> 
> We can change the title.

ok. Thanks for your trouble. 
 
> > 2. DNA Goal
> > I understand DNAv4 aims to detects movement (or lack of movement)
> > between subnets, and obtains (or continue to use) a valid IPv4 configuration.
> >
> > DNAv6 aims to detect movement (or lack of movement) between links
> > to ascertain the validity of existing IP configuration but does not include
> > the actual IP configuration procedure.
> 
> I think DNAv4 also ascertains the validity of an existing IP
> configuration.  If it is valid, then the host continues to use it.  But if
> it is not valid then the host needs to obtain a new configuration using
> mechanisms outside of DNAv4 (e.g. DHCP).  Is this different than DNAv6?

The difference I had in mind is whether DNA includes IP configuration or not. 
In DNAv6, Goals draft says:

                             DNA process does not include the actual
   IP configuration procedure.  For example, with respect to DHCP, the
   DNA process may determine that the host needs to get some
   configuration information from a DHCP server.  However, the process
   of actually retrieving the information from a DHCP server falls
   beyond the scope of DNA.

Whereas, I assumed that DNAv4 process includes actual IP configuration 
process because of "2.3.  IPv4 Address Acquisition". If not, I see 
little difference. 
 
> > 3. Point of Attachment
> > In DNA mailing list, we define a term "Attachment Point", which represents
> > the link-layer connection.
> >
> > For example, assume the case of two 802.11 b APs and a router on the same
> > ethernet link. Each AP is an Attachment Point and if a host moves from
> > one AP to another, it has moved to a different Attachment Point.
> >
> > It's my impression that the "Attachment Point" from DNA WG and
> > "Point of Attachment" from the draft doesn't mean the same thing.
> 
> In the case above, I think that the AP would also be called a "Point of
> Attachment", so they seem very similar.   I can change the document to say
> "Attachment Point" instead.

I might be mistaken. In the above example, I thought a router is the 
"Point of Attachment" because of the definition below.  

Point of Attachment
     A location within the network where a host may be connected.  This
     attachment point can be characterized by its address prefix and
                                                             
^^^^^^^^^^^^^^^^^^^^^^^^^^^
     next hop routing information.
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

If not, I see little difference and no need to change term. But it may 
be of help to present an example of "Point of Attachment".
  
> > Also I am glad & relieved to see that the draft no longer includes the term
> > 'link identifier'. Though the draft still uses the term 'link' a few times,
> > the meaning is clear from the context.
> 
> I did get questions about the meaning of terms such as "link", "Link Up",
> "Link Down" etc.  Perhaps I should post all the terminology that is used
> so that we can make sure we are consistent between DNAv4 and DNAv6.

That would be of help. While writing Goals draft for DNAv6, we had much 
trouble from the ambiguity around the term "link". I still worry the issue will 
come back again, so would be glad, if we set this straight.  

Thanks for your kind consideration. 

Best Regards

JinHyeock