How do I check open ports??

K

KamaL

n00b
Joined
Feb 9, 2002
Messages
62
Hi guys...

A simple question:

Is there a method to check out what open ports are available on my network through the firewall??

Is there a program that can do this??

I'm unable of connecting to IM programs... I want to check out why...


Thanx...
;)
 
I would recommend trying out NMAP, that would tell you what ports you have open on your firewall.
 
Originally posted by niccoli
I would recommend trying out NMAP, that would tell you what ports you have open on your firewall.
Click to expand...

Thanx..

But isn't there a normal setup file??? How do I use it??? It's seems quite complicated..
 
you can try shields up at www.grc.com. nmap seems complicated until you read the directions for all the settings. basically, the default scan method is pretty good anyway, so you really just need to type an IP in and press scan though.
 
Also remember, this may be obvious to some but not everyone. When you scan you network for open ports, you need to be on the OUTSIDE of you network. Scanning from the inside wont give you what you want. Easiest way to do this is use a switch BEFORE the firewall device.

Sorry if this is obvous to you, be surprised how many people do not think of this.
 
Originally posted by m1abram
Also remember, this may be obvious to some but not everyone. When you scan you network for open ports, you need to be on the OUTSIDE of you network. Scanning from the inside wont give you what you want. Easiest way to do this is use a switch BEFORE the firewall device.

Sorry if this is obvous to you, be surprised how many people do not think of this.
Click to expand...

yeah i was actually gonna mention that as a reason for using one of those online scans like at grc.com. another point to mention is that if you are not the network administrator, and do not have WRITTEN permission from the network admins to run a scan then you can get in a lot of trouble.
 
Ask one of your friends to donwload NmapWin, its easy to just do the default scan, and also to play around with the other scans.


Just dont do anything illegal!

NmapWin
 
Thanx for the replies...

So you guys say I have to be OUTSIDE the network, and make a scan...

But what do I have to point to??? to the IP of the router, or to a computer within the network??

I think I'm gonna try NMAPWin

thanx...;)
 
Originally posted by KamaL
Thanx for the replies...

So you guys say I have to be OUTSIDE the network, and make a scan...

But what do I have to point to??? to the IP of the router, or to a computer within the network??

I think I'm gonna try NMAPWin

thanx...;)
Click to expand...

Public facing IP, most likely that of the router.
 
you do NOT have to be outside the network to do the dslreports.com scan or the grc.com scan. that is why they were mentioned.
 
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