Which statement regarding TCP/IP packets is NOT true?

The statement that "TCP ensures no packets can ever be lost" is not true because while the Transmission Control Protocol (TCP) has mechanisms in place to detect lost packets and request their retransmission, it does not guarantee that packets will never be lost. In practice, various factors such as network congestion, hardware failures, or other issues can result in packet loss. TCP does provide a reliable communication service by ensuring that data is delivered in order and retransmitted if necessary, but it cannot eliminate the possibility of loss entirely.

In contrast, packets are indeed numbered to ensure proper message assembly, which helps the receiving system to reassemble the packets in the correct order, even if they arrive out of sequence. The ability for packets to take different paths to their destination is a fundamental characteristic of the Internet, allowing for greater efficiency and redundancy in data transmission. Additionally, fragmenting messages into packets helps improve overall reliability by enabling smaller bits of data to be sent, making it easier to manage errors and retransmissions.