how to monitor ports

mhm4 · #1 (**permalink**) 06-11-2007

I run into this issue occasionally and just looking for suggestions on how others solved it. I would like to monitor ports on a large number of systems and would like to determine which systems are listening on specific ports. I know there are heavy-weight apps that provide this such as HP ovo but I am looking for some light-weight open source options. I believe a syn scan will be sufficient for my purpose but I have not used any tools previously or not sure if their is a way to use default system tools or commands for this. Also for the those that have used syn scanning, does anyone run into issues due to simulating a syn attack in any of your networks?

Before you relpy, please do not recommend ping as it does not provide the functionality that I am looking for. Also, telnet will not provide this functionality because I do not what to have to script any break out or termination sequences for various connections (ie sendmail - port 25).

reborg · #2 (**permalink**) 06-11-2007

You could use nmap.

blowtorch · #3 (**permalink**) 06-11-2007

lsof might be another option here.

ghostdog74 · #4 (**permalink**) 06-11-2007

I use this Python script to check for port availability for my site. If you have Python, you are try this.

Code:

import socket
remote_host="localhost"
for remote_port in [22,901,139]:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(60)
        try:
                sock.connect((remote_host, remote_port))
        except Exception,e:
                print "%d closed " % remote_port                
        else: 
                print "%d open" % remote_port
        sock.close()

sysgate · #5 (**permalink**) 06-12-2007

GhostDog, nice one, I just changed it a little bit per my needs, thanks for sharing that.

Code:

#!/usr/bin/python

import socket
import sys

if ( len(sys.argv) != 2 ):
    print "Usage: " + sys.argv[0] + " you must enter IP or FQDN"
    sys.exit(1)

remote_host = sys.argv[1]

for remote_port in [22,80,8080,993]:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(60)
        try:
                sock.connect((remote_host, remote_port))
        except Exception,e:
                print "%d closed " % remote_port
        else:
                print "%d open" % remote_port
        sock.close()

JeepResQ · #6 (**permalink**) 06-27-2008

Good looking script to the both of ya! Gotta love python...or as I call it...miniJava in the Shell! lol

mhm4 · #7 (**permalink**) 06-13-2007

Thanks all for your feedback.
I was not aware for nmap. This looks like a great tool.
I love the simplicity of the python script also.
I believe lsof is for the local system, meaning that it must be installed on the local system to gather info which may not be effective for monitoring a large number of systems. Plus, one will have to handle remote login access to run the command.

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
Looking for monitor/top	pavelmac	UNIX for Dummies Questions & Answers	1	09-27-2005 11:12 PM
How to monitor pty	l-roner	AIX	2	07-08-2005 10:17 AM
PC monitor	mangolinux	SUN Solaris	1	02-14-2005 04:58 PM
Ports...	TechKnow	UNIX for Dummies Questions & Answers	5	05-20-2004 11:34 AM
Sun Monitor	Jai	UNIX for Dummies Questions & Answers	8	12-13-2001 01:12 PM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread:


	Powered by