@Tahoe
Correct.
And I'm sure I have opened what is neccessary to open.
@PVC
Yes my Amiga is connected to an external router.
But my ADSL-modem has more connections.
ADSL-modem (DHCP built-in, 4 x RJ45) -- Router (Firewall, DHCP)
Would it be possible to connect the Amiga to the ADSL-modem instead, since it still will have the same IP-adress (my ISP-adress) as it would be connected to the Router? But how to configure the Amiga to have port 20-21 open when using Miami DX?