What does the Frame Check Sequence (FCS) in an Ethernet frame ensure?

The Frame Check Sequence (FCS) is a crucial component of an Ethernet frame that is specifically designed to ensure data integrity. It achieves this by applying a cyclic redundancy check (CRC) to the data in the frame before it is transmitted. This CRC generates a checksum value that is appended to the frame, allowing the receiving device to perform the same computation on the received data to verify that it has not been altered or corrupted during transmission.

If the checksum computed by the receiving device matches the one included in the frame, it indicates that the data was received correctly and has maintained its integrity. If there is a mismatch, the receiving device can detect that there was an error during transmission and, depending on the protocol in use, it may request that the data be retransmitted. This capability is fundamental for maintaining reliable communication over networks.

While other options may relate to networking in some way, they do not pertain to the specific function of the FCS. Secure encryption, faster routing, and separation of data segments involve different mechanisms and processes that do not specifically focus on verifying the integrity of the data transmitted over the Ethernet frame.