This problem is best tested by an example, taken from [2] but a bit
modified.
Let's create hepothetical network issue with one forwarder, which worked
fine a while ago.
$ sudo iptables -I INPUT -i lo -d 127.0.0.255 -j DROP
Now start dnsmasq and send tcp query to it
$ dnsmasq -d --log-querie
Yes, dhclient generates DUID into its lease file. Either add -lf
/var/lib/dhclient/dhclient-$I.leases or just remove lease file after
each dhclient run. Parameter -D LLT might help too.
It should be visible what IPv6 address it is offering to the client in
logs. Does it change?
Petr
On 5/23
