The good news after all the work to get my homepage reachable again
is of course:
koos@greenblatt:~$ host idefix.net
idefix.net has address 82.95.196.202
idefix.net has IPv6 address 2001:888:1011::694
idefix.net mail is handled by 10 postbox.idefix.net.
My homepage is now reachable over IPv6!