Nmap Development: Re: a small doubt

["Dude VanWinkle" <dudevanwinkle () gmail com>]

On 4/28/07, Turbo <sandeep_kr () students iiit net> wrote:
> PS : I am new to this list. In case, my question is inappropriate here
> please ignore it or direct me to appropriate lists.
>
> I am trying to find out a list of all FTP servers on my college LAN using
> this command:-
> $ nmap -n -P0 -p 21 -oG ftpLog.gnmap -iL IPs.txt
>
> It returns 110 results. But when I remove -P0 option, it returns only 84
> results. Why? Am I doing something wrong?
the -P0 tells nmap "dont try and ping to see if a hosts is there, just
scan all the IP's" Thats why your scan will find more hosts, but also
take longer to complete. Some hosts dont reply to pings and therefore
will not be reported by a scan without the -P0, thats why you have
less hosts reported, but a faster scan time.

_______________________________________________
Sent through the nmap-dev mailing list
http://cgi.insecure.org/mailman/listinfo/nmap-dev
Archived at http://SecLists.Org