Final answer:
Two Mac computers can communicate if both IP addresses are on the same network and properly configured, even if one is self-assigned and the other is manually configured. A DHCP server is not necessary if the manual IP is correctly set.
Step-by-step explanation:
Whether two Mac computers can communicate with one another on a network depends on a number of factors, particularly whether they are configured correctly and are on the same network. One with a self-assigned IP address may indicate a problem with the device obtaining an IP address from the network, while the other with a manually configured IP address has been explicitly given its network address by the user. If both IPs are on the same network and properly configured, then communication is possible.
In general, the answer to whether these two devices can communicate is variable—it could be A) Yes, B) No, C) Communication may be intermittent but possible, or D) Only if a DHCP server is available to reconcile the self-assigned IP. However, the manually configured IP does not require a DHCP server as long as it is valid for the local network. Therefore, if both devices are set to the same IP range and subnet, and no IP conflicts exist, communication is indeed possible between them.