Re: [DNA] Prefix information for link identification in DNA

[Bernard Aboba <bernard_aboba@hotmail.com>]

>There are certainly adhoc networks in which there is no router.   However, 
>detecting attachment to such a network is quite difficult, because nodes 
>may join and leave and therefore there is no L3 invariant.  That is why the 
>DNAv4 reachability test cannot be used to detect attachment to adhoc 
>networks, but rather adhoc attachment is concluded after failiure of all 
>other approaches (reachability test, DHCPv4, etc.)

James Carlson has recently pointed out that there really is no intrinsic 
reason why DNA cannot be applied to networks without a router, and has 
proposed modifications to DNAv4 to allow this.  James has proposed that DNA 
be able to use any peer that is known to be stable as an indicator of 
network attachment.  This could be a router, or it could be another device.  
About the only fundamental limitation is that "network anchor" probably 
shouldn't obtain its address dynamically.

>>I would also agree that there are situations in which a network cannot be 
>>named using one of its prefixes.  In DNAv4, a private network is not 
>>suitable for identification because it is not unique.

Along these lines, James has also proposed that confirmation of a "network 
anchor" enable the plumbing of all network configurations relating to that 
anchor.  The result of this is that networks are not named using their 
prefixes;  they are named based on the IP address/MAC address of the network 
anchor.

It seems to me that James' comments apply equally to both DNAv4 and DNAv6 
and call into question some of the fundamental assumptions that have been 
made relating to DNA.