Determine which process opens a port?

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Scott Atchley Author

Level 4

2,225 points

Determine which process opens a port?

In Linux, I would simply use:

netstat -a -p

but that does not work on OSX. I have scoured the man page and tried apropos and found nothing. Any ideas?

PowerBook G4 1.67 GHz Mac OS X (10.4.2)

Posted on Mar 25, 2006 6:08 AM

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Answer 1

Jun T.

Level 4

2,191 points

Mar 25, 2006 7:19 AM in response to Scott Atchley

Hi Scott,

Try lsof
sudo lsof -i

HTH

PowerMac G4 Mac OS X (10.4.5)

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Answer 2

Camelot

Level 9

58,329 points

Mar 25, 2006 8:44 AM in response to Scott Atchley

If you know the port number in question, append that to the lsof command:

lsof -i :12345

will list all processes using port 12345. That'll be a much shorter list for you to scan through.

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Answer 3

Scott Atchley Author

Level 4

2,225 points

Mar 25, 2006 11:48 AM in response to Camelot

I tried this already. When I run

netstat -an

I see:

tcp4 0 0 192.168.1.103.5000 . LISTEN

but lsof reports nothing.

PowerBook G4 1.67 GHz Mac OS X (10.4.5)

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Answer 4

Mar 26, 2006 12:27 AM in response to Scott Atchley

Scott,

that's interesting that lsof didn't find anything.
did you run it like:

sudo lsof -i :5000

or

sudo lsof -i tcp:5000

if I remember correctly, you will need to use sudo,
otherwise, as you noted, you get nothing.

Andy

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Answer 5

Scott Atchley Author

Level 4

2,225 points

Mar 26, 2006 4:04 AM in response to Nils C. Anderson

Sudo was the missing element. Even on Linux, I use sudo to get netstat -p to work.

Thanks!

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Answer 6

Scott Atchley Author

Level 4

2,225 points

Mar 26, 2006 4:06 AM in response to Scott Atchley

The process is:

mDNSRespo 407 root 12u IPv4 0x01f90830 0t0 TCP 192.168.1.103:commplex-main (LISTEN)

I thought Bonjour worked on different ports and not the UPnP port.

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