Freeing up a TCP/IP port?

Question

netstat -tulnap shows me what ports are in use. How to free up a port in Linux?

Answer 1

To check all ports:

netstat -lnp

To close an open port:

fuser -k port_no/tcp

Example:

fuser -k 8080/tcp

In both cases you can use the sudo command if needed.

Answer 2

You can use tcpkill (part of the dsniff package) to kill the connection that's on the port you need:

sudo tcpkill -9 port PORT_NUMBER

Answer 3

In terminal type :

netstat -anp|grep "port_number"

It will show the port details. Go to last column. It will be in this format . For example :- PID/java

then execute :

kill -9 PID. Worked on Centos5

For MAC:

lsof -n -i :'port-number' | grep LISTEN

Sample Response :

java   4744 (PID)  test  364u  IP0 asdasdasda   0t0  TCP *:port-number (LISTEN)

and then execute :

kill -9 PID 

Worked on Macbook

Answer 4

Shutting down the computer always kills the process for me.

Answer 5

Kill the process that is listening to the port in question. I believe netstat shows you process ids.