Final answer:
To define the last host address on a network, the network address and subnet mask are needed. Without these, it's not possible to identify the last host address, which is typically one less than the subnet's broadcast address.
Step-by-step explanation:
To determine the last host address on a network, additional information is required such as the network address and the subnet mask. Without these details, we cannot ascertain the range of IP addresses within the network, thus making it impossible to identify the last host address. Typically, the last host address is the one before the broadcast address of a subnet. For example, if a subnet has a broadcast address of 192.168.1.255, then the last host address would usually be 192.168.1.254.