What is fragment-free switching?

Answer 1

Fragment free is a variation on cut-through switching that partially addresses this problem by assuring that collision fragments are not forwarded. This will hold the frame until the first 64 bytes are read from the source to detect a collision before forwarding.

This is only useful if there is a chance of a collision on the source port. Fragment-free switching is also known as runtless switching and is a hybrid of cut-through and store-and-forward switching. Fragment-free switching was developed to solve the late-collision problem.