topic Re: how to view the running application in particular ports in Operating System - Linux

how to view the running application in particular ports

senthil_kumar_1 — Thu, 23 Apr 2009 13:31:35 GMT

Hi

I am using Redhat linux. in that following ports are open 25,110,143,80,443.

I know that these ports for smtp,pop3,imap,http and https.

But I want to software name like sendmail / postfix and apache or any other we server.

So i want to know the exact application name running in particular ports.

Re: how to view the running application in particular ports

Ivan Ferreira — Thu, 23 Apr 2009 13:45:46 GMT

Use:

lsof -i :

# lsof -i :22
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
sshd 4855 root 3u IPv6 10866 TCP *:ssh (LISTEN)

Re: how to view the running application in particular ports

Steven E. Protter — Thu, 23 Apr 2009 13:49:42 GMT

Shalom,

I would want to know what is listening.

netstat -an | grep port_number

Then use lsof to get information on the process.

lsof -i 25
# May show multiple sendmail connections.

SEP

Re: how to view the running application in particular ports

senthil_kumar_1 — Thu, 23 Apr 2009 15:06:50 GMT

Hi

The command "isof" is not found in my
system.

How to install this.

Re: how to view the running application in particular ports

Steven Schweda — Thu, 23 Apr 2009 15:15:47 GMT

> The command "isof" is not found in my
> system.

Nor on anyone else's. "lsof". LSOF <> ISOF.

Re: how to view the running application in particular ports

Sivakumar MJ._1 — Thu, 23 Apr 2009 15:32:23 GMT

Senthil,

Check this...

http://www.opensource.apple.com/darwinsource/10.3/lsof-12/lsof/00QUICKSTART

Re: how to view the running application in particular ports

Heironimus — Thu, 23 Apr 2009 15:39:43 GMT

On Linux root can also use the "-p" option to have netstat display the process associated with a port.

Re: how to view the running application in particular ports

Steven E. Protter — Thu, 23 Apr 2009 16:28:08 GMT

Shalom,

It is standard install on RHEL.

/usr/sbin/lsof

rpm -qf /usr/sbin/lsof
lsof-4.78-3

This is off a RHEL 5.3 system.

That is the package you want to install.

-qf runs a query and asks what package provides the binary.

SEP

Re: how to view the running application in particular ports

Autocross.US — Thu, 23 Apr 2009 17:33:38 GMT

Run netstat with the following options to show all listening ports with the software name/PID:

netstat -tunlp

You can use grep to narrow it down:

netstat -tunlp|grep ":21" port 21)