Tim Chase blinux.list at thechases.com
Sat Jun 4 16:29:15 UTC 2011

On 06/03/2011 11:36 PM, marbux wrote:
> Might want to run a port-sniffer

If installed locally as an Apache (or lighttpd or lighty or ...) 
site, the web-server will open port 80 (HTTP) by default.  An 
XAMPP install may also open an administrative site, but if so, it 
should only listen on the loop-back interface.  If you're 
concerned about the web-server's open port, you can tweak the 
web-server's config file to only listen on the loop-back 
(, instead of *:80).

All that becomes somewhat moot if you're running behind a 
firewall/NAT, in which case unless you manually configure your 
router to redirect external port-80 requests to your internal 
machine, the only things that can connect would be on your local 

So to check for open ports, it's good to scan from the machine 
itself, from another machine on your network, and from a machine 
outside your provider's IP address (such as scanning your IP 
address from a local library/college or a friend's house).

To scan, assuming your IP address locally is and your 
external IP address (as determined from visiting 
http://whatismyipaddress.com ) is something like , you 
can scan local ports with:

   nmap localhost -p80  # see what can connect locally
   nmap -p80 # see what can connect from your LAN

and then from an off-site machine, run

   nmap -p80

to see whether external machines can connect to your box.  I all 
likelyhood, if you have a NAT router, the first two will 
successfully report the port open, but the offsite probe won't.


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