[kwlug-disc] Mysterious filtered ports on a server

Paul Nijjar paul_nijjar at yahoo.ca
Wed Oct 26 01:14:40 EDT 2016


On Wed, Oct 26, 2016 at 12:40:45AM -0400, Remi Gauvin wrote:
> On 16-10-25 11:56 PM, Paul Nijjar via kwlug-disc wrote:
> >
> 
> State: Filtered doesn't mean open,, it means firewalled. (ie, the
> packets are dropped).  *why* those ports are not responding at all
> when apparently you have no idea how to configure a firewall might
> be an equally interesting question.

I appreciate your help, but do not particularly appreciate the dig at
my ignorance. 

> Are you nmapping from outside the local network, (ie, might a Router
> be trying to forward those ports to a *different* host?)

Yes, I am nmapping from outside the local network, and that was the
clue that helped me solve this. Thanks. 

We are filtering outgoing connections on these ports on our local
firewall over these ports (which is why I recognised them). When I
disable that local rule then the "filtered" messages go away. 

> the output of iptables -v -L INPUT and iptables -v -L FORWARD might
> help illuminate things.

Both these commands just output the headers with no rules. You are
correct that I have never implemented a firewall on this machine. 

- Paul 

-- 
http://pnijjar.freeshell.org





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