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Full Discussion: Nmap
Special Forums Cybersecurity Nmap Post 17651 by LivinFree on Tuesday 19th of March 2002 04:04:17 AM
Old 03-19-2002
What kind of system are you scanning here? I know that on some (notably Redhat 7.2), firewalling is set up by default. When nmap finds a bunch of non-closed ports, it reports them as "interesting". UDP scanning is kind of tough, since it's "connectionless". But here's how nmap does it (from the man page):
Quote:
The technique is to send 0 byte udp
packets to each port on the target machine. If we receive an ICMP port
unreachable message, then the port is closed. Otherwise we assume it is
open.
This somewhat contradicts reality though, at least the way I see it. For example, I took a scan of an OpenBSD box (UDP only, default port selection), and it reported all 1453 ports as filtered. Go fig. Then again, it took 96 seconds on a 100base-t network on -T Insane, and reported the OS versions as "AIX 4.3.1 on a IBM RS/6000 R40"... Good ol' OBSD.

The best I can figure, is that if all ports are closed, it assumes it got no responses due to a packet filter - thus "filtered". But if you get at least one reply, the rest must just be closed... wild guess, though.

The important part though, is that you didn't see any open ports.
On a Linux system, you can also get a list of UDP ports with netstat -au... that is, assuming you haven't been cracked into and had your netstat replaced...

Hope this helps a little.
 

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XSetPointerMapping(3X11)					     MIT X11R4						  XSetPointerMapping(3X11)

Name
       XSetPointerMapping, XGetPointerMapping - manipulate pointer settings

Syntax
       int XSetPointerMapping(display, map, nmap)
	  Display *display;
	  unsigned char map[];
	  int nmap;

       int XGetPointerMapping(display, map_return, nmap)
	  Display *display;
	  unsigned char map_return[];
	  int nmap;

Arguments
       display	 Specifies the connection to the X server.

       map	 Specifies the mapping list.

       map_return
		 Returns the mapping list.

       nmap	 Specifies the number of items in the mapping list.

Description
       The function sets the mapping of the pointer.  If it succeeds, the X server generates a event, and returns Element map[i] defines the logi-
       cal button number for the physical button i+1.  The length of the list must be the same as would return, or a error results.  A zero ele-
       ment disables a button, and elements are not restricted in value by the number of physical buttons.  However, no two elements can have the
       same nonzero value, or a error results.	If any of the buttons to be altered are logically in the down state, returns and the mapping is
       not changed.

       can generate a error.

       The function returns the current mapping of the pointer.  Pointer buttons are numbered starting from one.  returns the number of physical
       buttons actually on the pointer.  The nominal mapping for a pointer is map[i]=i+1.  The nmap argument specifies the length of the array
       where the pointer mapping is returned, and only the first nmap elements are returned in map_return.

Diagnostics
       Some numeric value falls outside the range of values accepted by the request.
		 Unless a specific range is specified for an argument, the full range defined by the argument's type is accepted. Any argument
		 defined as a set of alternatives can generate this error.

See Also
       XChangeKeyboardControl(3X11), XChangeKeyboardMapping(3X11)
       X Window System: The Complete Reference, Second Edition, Robert W. Scheifler and James Gettys

															  XSetPointerMapping(3X11)
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