Re: NMAP Accuracy vs. Speed

[Mario Payán <mario () agora net mx>]

Hi,

maybe if you post the question to this mailling list you'll get a better
response:

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Hope this helps,

Mario


----- Original Message ----- 
From: <jburzenski () americanhm com>
To: <security-basics () securityfocus com>
Sent: Tuesday, March 23, 2004 9:14 AM
Subject: NMAP Accuracy vs. Speed


> I'm looking for any recommended settings for scripting nmap to accurately
> scan several large logically disperse networks.  My target list consists
of
> about 5 c-class networks that do not respond to ICMP and about 40 single
Ips
> that either do or do not respond to ICMP.
>
> I would prefer accuracy over speed if the scan times are reasonable.  I
have
> been -P0 on all scans since I can't reliably detect 100% of online hosts
> (which generates about 1.5MB of output in -oG format due to all of the
> filtered ports reported on).  Scans with -T 3 currently take about 8 days.
> Scans on -T 4 take about 1 day.  T 3 are noticeably more accurate and some
> networks report as no hosts online or ports open under T 4.
>
> Here is my current scanning command:
>
> nmap -T 4 -iL targetlist.txt -sT -P0 -oG output.log
>
> My goal is to maintain an updated list of target networks and use nmap to
> detect all open ports across the span monthly.  Then, another script will
> diff the outputs and report on any changes.  Eventually, I'll get a udp
> audit going as well.
>
> Any help would be appreciated.


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