Port monitoring using netstat

ZAMO · 08-19-2008, 02:46 AM

Hi all,

How can I find out whether the port 8840 is up on my Linux box?

Code:

$ netstat -na |grep 8840
tcp        0      0 :::8840    :::*                  LISTEN

Is this enough to confirm , that the port 8840 is up? Is there any better option there with netstat to make sure the port is opened?

Thanks

chort · 08-19-2008, 02:52 AM

A better way is

Code:

$ sudo lsof -nPi | grep \:<port number>

where <port number> would be 8840, or whatever you're looking for. That will tell if there's a process bound to that port. Whether it's "open" depends on your firewall configuration:

Code:

$ sudo iptables -nL

PS the output above indicates that 8840 is only bound to IPv6 addresses. Is there a typo, first you said 8840, then 8080. Which one are you looking for?

ZAMO · 08-19-2008, 02:58 AM

Thank you for the suggestions..

Yes, I made a typo... Am looking for 8840

farslayer · 08-19-2008, 08:17 AM

I usually do netstat -alnp | grep ::8840 that should return the process name that has the port open.

.i.e

Code:

it-etch:~# netstat -alnp | grep ::22

tcp6       0      0 :::22                   :::*                    LISTEN      3205/sshd