tcp syn, tcp syn ack, tcp syn flood, tcp_syncookies, tcp_syn_retries, tcp syn flag, tcp_syncnt, tcp_synack_retries, tcp_syn_sent, tcp_syn_flood, tcp_syn_recv, tcp_synmaxrtx, tcp_syn_retries linux, tcp_syn_retries timeout
tcp_syn. There are any references about tcp_syn in here. you can look below.