A control bit in the incoming segment, occupying one sequence number, used at the initiation of a connection, to indicate where the sequence numbering will start
A hacking technique used to cause a denial of service SYN packets are sent from a client with a spoofed IP address and are sent at a rate faster than the TCP stack on the host is set to time out As the client address is spoofed, the client sends no SYN-ACK, but continues to flood the host with SYN packets, tying up the resources of the host