Penetration Testing mailing list archives
Re: nmap udp scan time
From: Fyodor <fyodor () insecure org>
Date: Mon, 29 Oct 2007 23:15:32 -0700
On Fri, Oct 26, 2007 at 09:53:36AM +0200, Kevin Mc Grath wrote:
Hi all, I have completed a udp scan on an embedded device in the lab and the scan duration was 18.22 hours. The scan syntax used is as follows: nmap -sU -p0-65535 <ip_addr>
H Kevin. Many devices and operating systems limit ICMP port unreachable messages (the closed port response to UDP probes) to 1 per second. Divide 65536 scanned ports by 3600 seconds in an hour, and the fastest scan possible is 18.204 hours. This is why your scan took 18.22 hours. The good news is that Nmap can scan many of these hosts in parallel, so you could scan numerous targets in the same 18.22 hours. If you must complete your scan faster, you can try scanning from multiple systems (or just IP aliases on the same system). Usually the target devices allow 1 port unreachable response per destination IP per second. So if your Linux box has 5 IPs (even some home DSL accounts give you this many), you can do: nmap -S ip1 -sU -p0-13106 [target] nmap -S ip2 -sU -p13107-26213 [target] [etc] With 5 IPs, it should only take 3.6 hours. If you have 256 IPs (a class C), the scan should take less than 5 minutes. In other Nmap news, yesterday we released version 4.22SOC8 and we're looking for more testing in preparation for the upcoming stable release. You can find it at http://insecure.org/nmap/download.html (and learn about the recent changes at http://insecure.org/nmap/changelog.html ) Cheers, Fyodor ------------------------------------------------------------------------ This list is sponsored by: Cenzic Need to secure your web apps NOW? Cenzic finds more, "real" vulnerabilities fast. Click to try it, buy it or download a solution FREE today! http://www.cenzic.com/downloads ------------------------------------------------------------------------
Current thread:
- nmap udp scan time Kevin Mc Grath (Oct 26)
- Re: nmap udp scan time Gleb Paharenko (Oct 29)
- RE: nmap udp scan time Strykar (Oct 29)
- Re: nmap udp scan time Anders Thulin (Oct 29)
- RE: nmap udp scan time John Forristel (SunGard-Chico) (Oct 29)
- Re: nmap udp scan time Fyodor (Oct 30)
- <Possible follow-ups>
- Re: nmap udp scan time jpecou (Oct 29)
- Re: nmap udp scan time jason_jones98 (Oct 30)