ESTABLISHED : now connecting
LISTENING : wait for connect
TIME_WAIT : Disconnect or wait for next connection
SYN_SENT : sended packet to connect

netstat     : connecting port
netstat -a : show us all port ( connecting or listening ) 
netstat -n : show ip instead of computer's name
netstat -na | grep portnumber
netstat -nap
netstat -nap | grep:80 | grep ESTABLISHED | wc -l ( web coinside visitor..?)

port is wheter open or close ?

bind() function isn't closed by now. so netstat use, you can find port is open(WAIT_TIME)

how to solve abind() function error problem
 - TIME_WATE STATE is wait for client's ACK

so, client program must transfer ACK signal.

and if you see many SYN_RECV your netstat report, you can suppose attempt to DDOS attack.
이 게시물을...