Net filtering puzzle

Tony Arnold tony.arnold at
Thu Jun 9 14:32:52 UTC 2005

On Thu, 2005-06-09 at 16:17 +0200, Dennis Kaarsemaker wrote:
> On do, 2005-06-09 at 16:01 +0200, Dennis Kaarsemaker wrote:
> > * Even nmap shows these ports as filtered
> nmap $ip from another machine show filtered
> nmap $ip from the machine itself shows open.
> This indicates to me that the filtering is done outside the machien
> self, is this correct?

Given that iptables -L is empty, then I think this must be true,
although it is possible to set up a filtering rule on the machine which
allows connections from the local host, but not from a non-local host.

Have you done a 'netstat -l' to see you what ports are being listened

Tony Arnold, IT Security Coordinator, University of Manchester,
IT Services Division, Kilburn Building, Oxford Road, Manchester M13 9PL.
T: +44 (0)161 275 6093, F: +44 (0)870 136 1004, M: +44 (0)773 330 0039
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