Security Basics mailing list archives
RE: Data Interpretation
From: "David Gillett" <gillettdavid () fhda edu>
Date: Thu, 19 Mar 2009 17:43:06 -0700
On 2009-03-17 David Gillett wrote:Neither of these things is happening, and nmap can't tell why not. SOMETHING must be listening, since no ICMP packet wasreceived back,but clearly it's not a normal process. The most likely scenario is that a firewall or other security measure is dropping theSYN packetwithout deigning to respond.Packet filters aren't really listening (at least not in the TCP sense of the word).
Agreed, although I'd say that this is closer to the English definition of listen than the TCP sense which carries additional implications.
This is, in fact, exactly what you want.I have to disagree. What you actually want in a situation like that is the firewall to respond with a RST.
I'm aware of arguments for and against sending an RST; I considered them beyond the scope of the present question. But certainly if these services were merely unsupported and not actively hostile, sending an RST would be the correct and polite thing to do. And that would tell nmap that the port was actively being blocked.... David Gillett ------------------------------------------------------------------------ This list is sponsored by: InfoSec Institute Find the source of cybercrime! Almost every crime today involves a computer or mobile device. Learn how to become a Computer Forensics Examiner in InfoSec Institute's hands-on Computer Forensics Course. Up to three industry recognized certs available, online computer forensics training available. http://www.infosecinstitute.com/courses/computer_forensics_training.html ------------------------------------------------------------------------
Current thread:
- Data Interpretation Michael Lynch (Mar 16)
- RE: Data Interpretation Javier Becerra (Mar 17)
- Re: Data Interpretation Derek Robson (Mar 17)
- Re: Data Interpretation Ansgar Wiechers (Mar 17)
- RE: Data Interpretation Alexis Grigoriou (Mar 17)
- Re: Data Interpretation τ∂υƒιφ * (Mar 17)
- Re: Data Interpretation Ansgar Wiechers (Mar 17)
- RE: Data Interpretation David Gillett (Mar 17)
- Re: Data Interpretation Ansgar Wiechers (Mar 19)
- RE: Data Interpretation David Gillett (Mar 20)
- Re: Data Interpretation Ansgar Wiechers (Mar 24)
- Re: Data Interpretation David Schekaiban (Mar 17)
- <Possible follow-ups>
- FW: Data Interpretation Murda Mcloud (Mar 19)