When you promote a server to a DC, DNS is installed and setup as part of this process. You want your client systems pointed to your DC's for DNS resolution. On the windows DNS, set your Astaro as a forwarder. On the Astaro box, in DNS, set the external DNS servers of your preference as forwarders. You'll also want to create a couple of request routes, one each for forward and reverse lookups for your internal domain back to your DC/WinDNS.
__________________ ACE v8/SCA v9.3
...still have a v5 install disk in a box somewhere.
When you promote a server to a DC, DNS is installed and setup as part of this process. You want your client systems pointed to your DC's for DNS resolution. On the windows DNS, set your Astaro as a forwarder. On the Astaro box, in DNS, set the external DNS servers of your preference as forwarders. You'll also want to create a couple of request routes, one each for forward and reverse lookups for your internal domain back to your DC/WinDNS.
__________________ ACE v8/SCA v9.3
...still have a v5 install disk in a box somewhere.