full-disclosure - closing ports

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From: hena at hack.fi (hena)
Subject: closing ports

Hi.

if your running linux try something like
iptables -t filter -A INPUT -p tcp -s 0.0.0.0 --syn -j REJECT
--reject-with tcp-reset

this way you get ALL the ports closed, even the local range ports and
still have a working connection, then open the ones you need to have
open. The --syn flag drops all packets that have syn bit enabled and 
ack bit not(these are the connection initiation packets).

On Fri, 2003-11-07 at 09:50, Christ-Henning Ljosheim wrote:
>  
> Hi 
> I am new in this group (from Norway)
> Do you have any tips for which ports I should close to held my network
> clean for intruders ?
> I've closed port 1214 and 6881 to 6889 . Anyone else I should close ?
>  
> Chris