RE: [DNA] Some questions about Simple DNA

[Bernard Aboba <Bernard_Aboba@hotmail.com>]

> By definition, for a host to do DNAv6, it has already completed
> duplicate address detection on the address.  Why should the host
> be required to do (Optimistic) DAD every time it awakes from sleep?
> Given the duty cycles we are now seeing, this means that the host
> will never obtain a usable address!

This is to deal with another host picking up the same address after the 
host went to sleep/left the link. The new host thinks that its address 
is unique while in fact it is not. I do not see any other way around this.

[BA] In the case of an address obtained from DHCPv6, where the lease is
still valid, the host had previously done DAD and a compliant DHCPv6 
server will not give out the same address to multiple hosts.  So why 
should the host do DAD again? 

Also, if the host has not been gone from the network more than the
time required for DAD to complete, then it could not have missed a
DAD attempt from another host.  

Therefore I do not see a reason why a mobile host that is moving
between points of attachment on the same LAN should be required to
do DAD each time it connects to a new AP.