No internet connection Error - Firewall configuration?

We are also experiencing a no internet connection error. This is inconsistent and we have some questions that may help us understand/resolve the issue at our end:

• What Fully Qualified Domain Name(s) (FQDN) would be required to be added to our firewall to allow traffic to flow both in and out of our firewall's perimeter in order to allow our Pinnacle 21 Community software (v3.0.1) to function properly?
• What TCP/UDP ports should be associated with the FQDNs?
• Further, how can we determine from our installed ‘client’ software what Pinnacle 21 server(s) we are using? Is this possible? As it could help determine what is and is not working for us.