Which switching mode stores the first 64 bytes before forwarding, serving as a transitional technique?

• A. Fragment-free
• B. Store-and-forward
• C. Cut-through
• D. Frame-switching

Answer: (A)

Fragment-free is a hybrid switching mode that buffers and forwards after the first 64 bytes have been received. In Ethernet, 64 bytes is the minimum frame size, and a collision can corrupt a frame early in transmission. By waiting for the initial 64 bytes, the switch can verify that the frame is not a fragment caused by a collision before forwarding, then continues sending the rest of the frame. This provides a middle ground between the ultra-fast but less-safe cut-through method (which starts forwarding as soon as the destination address is read) and the fully cautious store-and-forward method (which waits for the entire frame). It reduces the chance of propagating corrupted frames while still offering lower latency than waiting for the whole frame.