A combined SYN attack with IP spoof is referred to as
Land attack. A Land attack occurs when an attacker sends
spoofed SYN packets containing the IP address of the victim as
both the destination and source IP address. The receiving
system responds by sending the SYN-ACK packet to itself,
creating an empty connection that lasts until the idle timeout
value is reached. Flooding a system with such empty connections
can overwhelm the system, causing a DoS.
This attribute records the land attack packets.