how to know about ports

divyashree · 03-29-2009, 02:05 AM

How will I know which of my ports are opened and closed ????

win32sux · 03-29-2009, 02:49 AM

Quote:

Originally Posted by divyashree

How will I know which of my ports are opened and closed ????

Run a port scanner such as nmap against your interface?

centralb · 03-29-2009, 02:50 AM

You can view listening ports as root with

Code:

netstat -apnt | less

You can view the number of open connections per IP with:

Code:

netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

Both depend on your distribution.

win32sux · 03-29-2009, 03:09 AM

Quote:

Originally Posted by centralb

You can view listening ports as root with

Code:

netstat -apnt | less

Keep in mind this won't show you the actual state of the ports. For example, the output of that command might tell me that I have something listening on port 80 when it is completely firewalled, thereby showing a state of "closed" to an actual port scanner. If you want to be sure, you need to scan from a separate box.

BTW, please remove the non-English parts from your signature, otherwise you are not complying with the LQ Rules. If you have any questions or comments about this matter, contact me via email. Do not use this thread.

sigey · 03-29-2009, 03:50 AM

what i normally use on redhat is the handy command netstat --inet -a
ofcourse i think nmap is the most quick and easy way to do it.

thanks.

H_TeXMeX_H · 03-29-2009, 03:51 AM

Usually I do 'nmap localhost'.

divyashree · 03-29-2009, 04:56 AM

Thanks to all,I found my answer but how will I close my open ports,only by stopping the services or any method ????

win32sux · 03-29-2009, 05:01 AM

Quote:

Originally Posted by divyashree

Thanks to all,I found my answer but how will I close my open ports,only by stopping the services or any method ????

Yes, you can either stop whatever service is listening on the ports, or you can set up a firewall.

win32sux · 03-29-2009, 05:08 AM

Quote:

Originally Posted by H_TeXMeX_H

Usually I do 'nmap localhost'.

That's not gonna tell you what your ports look like to the bad guys, though.

win32sux · 03-29-2009, 05:09 AM

Quote:

Originally Posted by sigey

what i normally use on redhat is the handy command netstat --inet -a
ofcourse i think nmap is the most quick and easy way to do it.

Again, the information provided by those two commands is completely different.

Neither of those command is a substitute for the other.

H_TeXMeX_H · 03-29-2009, 05:42 AM

Quote:

Originally Posted by win32sux

That's not gonna tell you what your ports look like to the bad guys, though.

Then use an online port scanner. Search google for them.

win32sux · 03-29-2009, 06:11 AM

Those online port scanners are a good option. Although, personally, I just stick to nmap.