You need to make sure that your network is configured to allow the Management Service, Policy Distribution Service, and Security Client to find and communicate with one another.
Management Service to Policy Distribution Service: If the two services will be on different servers, make sure that Management server can successfully ping the Policy Distribution server. If the Policy Distribution server is inside the firewall, you can use the local (NETBIOS) server name or the server’s Fully Qualified Domain Name (FQDN). If the Policy Distribution server is outside the firewall, use the server’s FQDN.
Security Client to Policy Distribution Service: Make sure that endpoint devices (where the Security Client will be installed) can successfully ping the Policy Distribution server.
Security Client to Management Service: Make sure that endpoint devices (where the Security Client will be installed) can successfully ping the Management server.