This read-write switch enables or disables the "TCP Fragment" Denial-of-Service protection feature, which screens fragmented TCP packets for attack patterns. Admins enable it to defend against attacks that exploit IP fragmentation of TCP segments, such as fragment overlap or tiny-fragment techniques designed to slip malicious data past firewalls or crash a target's reassembly logic. For example, turning this on protects hosts behind the switch from a crafted stream of overlapping TCP fragments intended to bypass packet inspection.