Take advantage of TCP/IP ... the SYN/ACK, the packet server wakes up a receiver process while waiting for data. When the three-way handshake is completed, the client starts to send “useful ...

the server system is under a large tcp load when it fails to respond ... sackOK> (DF)<BR><BR>-> THIS IS WHERE A SYN-ACK SHOULD BE SENT <-<BR><BR>client resends syn:<BR>11:15:10.484739 0:30:1b ...

I believe that in Linux that signifies that it received a SYN packet, probably sent a reply and is waiting ... well so it appears to be across all TCP protocols and therefore easy to duplicate.