Re: how to find out a list of available ftp servers on LAN

[Lukasz Szmit <lukasz.szmit () ucd ie>]

On Sun, 2007-04-29 at 05:28 +0530, Turbo wrote:
> I am using following command :-
> nmap -n -P0 -p 21 -oG ftpLog.gnmap -iL IPs.txt
> Are their other better options? or improvements to above command?
> It takes around 7 mins to scan a list of 8960 IPs. Its ok, but I am still 
> looking for faster options.


I'd use:
nmap -n -P0 -sT -p 21 --max-retries 0 --open -oG ftpLog.gnmap -iL
IPs.txt


If you're trying to discover accessible FTP' on you LAN, Connect scan
(-sT) is fine, otherwise use SYN (-sS) which *may* bypass some firewalls
and give better results.

Setting max-retries to 0 will result in nmap sending just a single probe
- this gives a significant improvement in scan time on my box for a /24
compared to defaults (1.172 seconds vs. 14.754 seconds). You may miss
some slow-to-respond boxes.

The --open option will spare you some noise in the output as
closed/filtered ports won't be reported.

regards,
-- 
Lukasz Szmit
UCD, Dublin