On Wed Jan 03 12:58:01 2018, tmark wrote:
> On Sun Dec 24 12:01:57 2017, fdupont wrote:
> > I reopen this because IMHO it should warn more
> > about the backward incompatible change for
> > the DHCPv6 client.
> 
> There is nothing backwardly incompatible with this change. The new
> behavior only occurs if the user specifies the new command line
> argument. Without it, dhclient behaves as it did prior to this.

=> Moving from address/64 to address/128 IS INCOMPATIBLE!!!

To get back previous behavior during port relay tests I had
to add the new parameter and to enforce the new script.
I kept full commands for DHCPv4-over-DHCPv6, here is
the DHCPv6 client part:

./dhclient -d -v -6 -4o6 6767 -lf /tmp/lease6 -pf /tmp/pid6
 --address-prefix-len 64 -sf ./scripts/linux ens38