dhclient -6 handling of IPv6 Duplicate Address Detection

[Patrik Lahti]

Hi all,

When assigning an IPv6 address a node performs Duplicate Address 
Detection (DAD, RFC 4862). And as expected this is triggered by the OS 
stack when dhclient -6 configures an address via the dhclient-script. 
However, if the address is found to be duplicate, i.e. when DAD fails, I 
don't see a Decline and an attempt to retry (RFC 3315, section 18.1.8). 
It seems the dhclient goes on unaware of what occurred...

Is this a known problem? With known solutions? Should dhclient handle 
this, or is the intent that an outside entity (e.g. the dhclient-script) 
do it? (is it ok to sleep in the script while DAD is performed or will 
that mess up some dhclient timing)

Regards and Thanks in advance,
/P

PS. I saw 
https://lists.isc.org/pipermail/dhcp-workers/2010-February/000108.html 
but couldn't find a response...