I'm not sure you even need the extra router; the Astaro can take the place of both the ASA and the router, unless you are using that router for multiple WAN / LAN networks, etc. YOu can place one interface on the outside (using the public IP), and the internal network and any DMZs on other interfaces or VLANs, and just use the NAT/DNAT/SNAT/MASQ function of the Astaro to connect the inside to the outside.
