$packet = new Net::RawIP({tcp => {}});
$packet->set({ip=>  {saddr=>$srcip, daddr=>$dstip, frag_off=>0, tos=>0
+, id=>int rand 50000},
              tcp=> {source=>$sport, dest=>$dport, syn=>0, ack=>1, win
+dow=> 65535,
                         ack_seq=>++$his_seq, seq=>++$my_seq,}});
$packet->optset(tcp=> { type => [(3)], data => [(2)],});