Nmap Development: Re: sometimes, a scan shows filtered..

[root <root () elxsi de>]

On Sat, 17 Aug 2002, Roeland Th. Jansen wrote:

Hi,
have a look at the nmap manpage:

<quote>
The result of running nmap is usually a list of  interest-
ing  ports on the machine(s) being scanned (if any).  Nmap
always gives the port's  "well  known"  service  name  (if
any),  number,  state,  and protocol.  The state is either
'open', filteredtoday , or a unfilteredfriend .  Open means that
the target  machine  will  accept()  connections on that port.


==> Filtered means that a firewall, filter, or  other  network
obstacle  is  covering  the  port and preventing nmap from
determining whether the port is  open.   Unfiltered  means
that  the  port is known by nmap to be closed and no fire¡
wall/filter seems to be interfering with  nmap's  attempts
to  determine  this.  Unfiltered ports are the common case
and are only shown when most of the scanned ports  are  in
the filtered state.


Martin

> of mine and I were experimenting against his windows
> machine and consecutive scans show consistently all the specified scan
> ports closed.
>
> but sometimes, I see a weird thing. instead of reporting the ports to be
> closed, it reports :
>
> 1214/tcp   filtered    kazaa
> 1503/tcp   filtered    imtc-mcs
> 1720/tcp   filtered    h323hostcall
> 1863/tcp   filtered    msnp
>
> which happen to be the four ports we were experimenting with. since
> it;'s closed, no problem but it struck me that it was filtered.
>
> why ?
>
>
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---------------------------------
Paranoia heisst nur die Wirklichkeit realer zu sehen, als andere.

Name    : Martin Kluge
email   : martin () elxsi info
Phone   : +49 160 1530201
Projects: http://www.aa-security.de



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