A communication apparatus which is capable of performing multicasting or broadcasting using a user-desired network interface. An MFP implementing the communication apparatus includes a plurality of network interfaces and performs multicasting or broadcasting via at least one of the network interfaces. A controller unit provides an application programming interface to an application that operates on the MFP. An operator of the MFP operates an operation unit to set a transmission condition for transmitting a multicast packet and a broadcast packet via a predetermined network interface. When a plurality of active network interfaces are detected, one of the plurality of detected active network interfaces which satisfies the set transmission condition is selected and multicasting or broadcasting is performed via the selected network interface.