Which piece of information is not vital for a computer in a TCP/IP network?

In a TCP/IP network, the piece of information that is not vital for a computer to function is the computer’s physical (MAC) address of the destination computer for communication over the internet. This is because, in a TCP/IP network, communication across the internet is based on IP addresses. The MAC address is crucial for local network communications within the same network segment, but when communicating over the internet, routers use IP addresses to forward packets to the correct destination. Routers along the path make forwarding decisions based on the destination IP address, not the MAC address, which is mostly used within the local subnet to direct packets at the link layer (Ethernet layer in most cases).