How to configure iptables so an unwanted port is not reported as filtered

Solution 1:

Don't use DROP, that's easily identified as "filtered" if you know the box is up. Instead, you may use the following to send a RST. (as if there is a service listening, but it doesn't accept connections from you)

-A INPUT -p tcp -m tcp --dport 22 -j REJECT --reject-with tcp-reset

Or otherwise simply use the following to make the port look closed. (as if there is no service listening on it)

-A INPUT -p tcp -m tcp --dport 22 -j REJECT

Solution 2:

-A INPUT -p tcp -m tcp --dport 995 -j REJECT --reject-with tcp-reset

should be doing what you want (reply with RST).