how to check which process is using a particular port# ?

[Kenneth Leung_2]

My application use a particular port# for connection. Now, it didn't work & I think the port is occupied by some zombie process. How can I find out the process to kill? Please help. Thanks a lot.

[Michael Steele_2]

Can you paste in your 'netstat -an' report? This will id server processes attached to a port. There are also sniffers like tcpdump and etheral and 'lsof' can provide a lot of information.

[Rajeev Shukla · Accepted solution]

If your port number is listed in the /etc/services file then run
lsof|grep port_name(as show in /etc/services file) or just grep the port number
lsof |grep port_num
this will give you the application and the PID using that port

[Yogeeraj_1]

hi,

There exists the lsof utility which is available at:
ftp://vic.cc.purdue.edu/pub/tools/unix/lsof/

E.g. if you are getting a message that the port xx is in use. You then run netstat -a | grep to see if the port is in use.

You can determine which process by running: lsof -i TCP:. You can then decide whether to kill the process.

hope this helps!

kind regards
yogeeraj

[Senthil Prabu.S_1]

Hi,
You can confirm whether that particular port is opened or not by netstat -na.

then, you need to run "lsof" command to find the process number of the service that is using the port.

Then kill it using kill -9 command.


Note:
If you dont have lsof utility installed on your machine. Download it from;
http://hpux.connect.org.uk/hppd/hpux/Sysadmin/lsof-4.77/


HTH,
Prabu.S