Home page logo
/

fulldisclosure logo Full Disclosure mailing list archives

Re: Nmap
From: "Zach C." <fxchip () gmail com>
Date: Tue, 3 Jan 2012 03:37:21 -0800

Yet another note, this one ARP-related: while true that most devices on
your local network will respond to ARP, it's important to note (as the
wording of "almost certain" implies) that it is possible to purposely
suppress ARP responses to all but a few hosts. I know for certain that the
Linux kernel has a module (and associated toolset) specifically for that
sort of thing called arptables, with usage very similar to iptables if
you're already familiar with that.

There's also a tool (again on *nix) called arping, which is ping but with
ARP requests. Device firewalls (or at least Windows's built in firewall)
tend(s) not to block ARP requests or replies, so arping might be able to
show you those firewalled hosts, too. (That doesn't mean those hosts aren't
properly configured to correctly block incoming traffic, however!)

On Mon, Jan 2, 2012 at 2:10 PM, Gage Bystrom <themadichib0d () gmail com>wrote:

(I don't have the original, so ill qoute this guy)

Nmap has an option to change how it determines if a host is up by
attempting a port connection instead. I find this to be highly effective.
Using a couple of standard ports are the best, such as 80, 21, etc. If you
only have a few ports your searching for, then drop host discovery and scan
those specific ports, youd get the same results but a tad bit less
overhead(mainly in the sense of stealth or an obsession with not wasting
bandwidth if you can help it)
On Jan 2, 2012 1:00 PM, "S Walker" <walker_s () hotmail co uk> wrote:


Just an added note to the current replies (which are all great for hosts
not in the local broadcast domain): It is almost certain that every device
in your local network will respond to an ARP request. nmap does this by
default anyway (-PR for local networks), but it's worth bearing in mind, as
something local that won't respond to an ARP request is almost certainly
not reachable.

S

----------------------------------------
Date: Mon, 2 Jan 2012 12:03:42 -0500
Subject: Re: Nmap
From: juan.quine () gmail com
To: pen-test () securityfocus com

Sorry for the late answer...

But when you scan for machines that do not answer to ping (it means
answer with an echo reply for each echo request), you could try using
timestamp, and will return timestamp reply, and also information
request and wait for an information reply

Both coould be useful also to detect equipments that do not answer to
ping. And if you want something more "noisy" maybe a network discovery
or a -P0 option.

Here is a summary of message types with their port (for ICMP protocol).

0 Echo Reply
3 Destination Unreachable
4 Source Quench
5 Redirect
8 Echo
11 Time Exceeded
12 Parameter Problem
13 Timestamp
14 Timestamp Reply
15 Information Request
16 Information Reply

More detail on: http://www.faqs.org/rfcs/rfc792.html

Hope it will be useful.

Regards,

Juan Pablo.

On Sun, Oct 2, 2011 at 4:35 PM, John M. Martinelli
 wrote:
This would work but it would be kind of "noisy" to open port scan
every host. Also probably a little more time consuming.

Adding in syn scan or open port scan will create more time required as
we're now looking for open ports. What if all ports are closed? Will
it respond to a certain type of ICMP?

I think a great question to ask is: "What is the least-impactful way I
can very quickly determine what hosts are alive?" without a
traditional ping sweep.

On Sat, Oct 1, 2011 at 10:37 PM, Jeffory Atkinson  wrote:

All depends on what you are trying to achieve. I would assume that
you are not concerned about monitoring devices seeing you have done a ping
sweep with nmap. I agree with others a port scan is going to give you the
best idea if a host is active. There are Many instances filtering devices
can drop icmp or respond for hosts behind them.  Open ports and services
are the best identifiers. A port has to be open in some form (open or
filtered) to interact with in-bound connections. I would recommend a -sS
(syn) scan you can opt for standard services or add -p1- for all 65k+
ports. All ports will verify and services/demons running. There are other
options if bandwidth is an issue.


On Sep 30, 2011, at 5:17 PM, Ukpong  wrote:

Can somebody suggest the best NMAP commands for identifying hosts
that
are not responding to ICMP ping requests ?


------------------------------------------------------------------------
This list is sponsored by: Information Assurance Certification
Review Board

Prove to peers and potential employers without a doubt that you
can actually do a proper penetration test. IACRB CPT and CEPT certs require
a full practical examination in order to become certified.

http://www.iacertification.org

------------------------------------------------------------------------



------------------------------------------------------------------------
This list is sponsored by: Information Assurance Certification
Review Board

Prove to peers and potential employers without a doubt that you can
actually do a proper penetration test. IACRB CPT and CEPT certs require a
full practical examination in order to become certified.

http://www.iacertification.org

------------------------------------------------------------------------



------------------------------------------------------------------------
This list is sponsored by: Information Assurance Certification Review
Board

Prove to peers and potential employers without a doubt that you can
actually do a proper penetration test. IACRB CPT and CEPT certs require a
full practical examination in order to become certified.

http://www.iacertification.org

------------------------------------------------------------------------




--

===============================================
|_|0|_| Ing Juan QuiƱe, CISSP, OSCP, GISP, ISO 27001 LA, Cobit-F.
|_|_|0| visita: http://hackspy.blogspot.com/
|0|0|0| a.k.a. HaCKsPy - from Security Wari Projects, now PeruSEC

"... hacking is a way to live your life, not a day job or semi-ordered
list of instructions found in a thick book ..." Anthony Bunyan
"... Live your life as if you will die tomorrow but learn as if you
will live forever ..." Mahatma Gandhi
"... Romper un sistema de seguridad los acerca tanto a ser hackers
como encender autos puenteando cables los convierte en ingenieros
automitrices ..."
"... Nada es tan importante, ni tan urgente que no pueda ser hecho con
seguridad ..."

------------------------------------------------------------------------
This list is sponsored by: Information Assurance Certification Review
Board

Prove to peers and potential employers without a doubt that you can
actually do a proper penetration test. IACRB CPT and CEPT certs require a
full practical examination in order to become certified.

http://www.iacertification.org
------------------------------------------------------------------------


------------------------------------------------------------------------
This list is sponsored by: Information Assurance Certification Review
Board

Prove to peers and potential employers without a doubt that you can
actually do a proper penetration test. IACRB CPT and CEPT certs require a
full practical examination in order to become certified.

http://www.iacertification.org
------------------------------------------------------------------------


_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

  By Date           By Thread  

Current thread:
  • Re: Nmap Gage Bystrom (Jan 02)
    • Re: Nmap Zach C. (Jan 03)
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]