If you defined your own external and internal FQDN while installing 3CX in a NATed environment, how many A records must you create?

When installing 3CX in a NATed environment and defining your own external and internal Fully Qualified Domain Names (FQDN), you will need to create two A records.

The rationale behind this requirement is rooted in the function of FQDNs in directing traffic to the appropriate local resources. The internal FQDN is used for communication between devices within the local network, allowing them to resolve the name to the local IP address. Conversely, the external FQDN is utilized by clients outside the network to connect to the 3CX server, ensuring that they can resolve to the public IP address for accessing the service.

In summary, having both A records—one for the external FQDN pointing to the public IP address and one for the internal FQDN pointing to the local IP address—is essential for proper functionality and to facilitate seamless communication for both internal and external clients. Therefore, creating two A records is necessary to enable the system to operate effectively in a NATed environment.