Track open port to application

newbe45 · 09-11-2007, 01:48 PM

I recently inherited a file server that is running BSD. There seems to be an FTP service running and I can't seem to find it. Port 21 is open. Doing grepping the running processes for ftp returns nothing. Is there a way I can find out what has port 21 open?

bathory · 09-12-2007, 01:53 AM

Usually the ftpd service is running through inetd. I.e. when a request reaches port 21 then it's inetd that passes control to ftpd to start the file tranfer. You can read more about inetd here.

Regards

asimba · 09-13-2007, 09:08 AM

Check if this works

netstat -anp | grep 21

newbe45 · 09-13-2007, 11:09 AM

Quote:

Originally Posted by asimba

Check if this works

netstat -anp | grep 21

Well that pulled up some info that port 21 is in a listening state but no other info.

lolo2kx · 09-14-2007, 12:54 AM

Not sure about the BSD side... But from linux I'd go with the lsof utility... Commonly /usr/sbin/lsof or something similiar... Run it and grep the output as mentioned in the other post with netstat...

lsof | grep 21

You may get quite a few results because 21 isn't all that unique but hopefully it will shed some light on your situation...

doublejoon · 09-14-2007, 11:12 AM

Code:

lsof -i tcp:21

look at the PID column for Process ID
then

Code:

lsof -p your PID

This should list the full path to the actual daemon and related libraries