I see these entries in my syslog every few days, what does it mean?
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:48:12 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:48:12 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:44:18 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:48:12 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.
Jul 3 20:48:12 kernel: TCP: Possible SYN flooding on port 18099. Sending cookies.