Which parameter is not required for configuring Ethernet communication?

The parameter that is not required for configuring Ethernet communication is the encryption key. In the context of basic Ethernet communication setup, the primary focus is on the unique identifiers and routing needed for devices to communicate over the network.

To establish communication, an IP address is needed to uniquely identify a device on the network, while the subnet mask helps define the network boundaries and allows devices to understand which part of the address represents the network and which part represents the host. The MAC address, also essential, serves as a hardware address that identifies the physical device on the local network segment.

In contrast, an encryption key relates to security protocols that may protect data during transmission but is not a fundamental requirement for Ethernet communication itself. Basic communication can occur without any security measures in place, making the encryption key non-essential for the configuration of network settings specifically related to Ethernet.