From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacob Friis Larsen Subject: Re: Port is open but I am unable to connect Date: Wed, 08 Sep 2004 08:47:18 +0200 Sender: netfilter-bounces@lists.netfilter.org Message-ID: <413EAAF6.5030804@list.idg.dk> References: <413E0B9E.8010708@list.idg.dk> <413E2123.6050908@pbl.ca> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <413E2123.6050908@pbl.ca> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: netfilter-bounces@lists.netfilter.org Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Aleksandar Milivojevic Cc: netfilter@lists.netfilter.org > All your rules (apart from lo interface) are for INPUT chain. No rules > for OUTPUT chain (so all return packets get dropped there). You are > missing "-A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT" at > the begining of your rules (just after similar INPUT line you already > have). Sounds logic. I changed it in the script below, and will try it out later when I can get to the server. > BTW, what's the point of accepting connections to port 20? It's FTP > port used for active data transfers, and connections are made *from* > it, not *to* it. Since you have (will have) "just accept anything > related I don't care" rules, just add "modprobe ip_nat_ftp" line > somewhere into your script, and FTP will work (you don't need that > port 20 line). OK, I changed that too. Thanks a lot! Jacob >> This is my script: > > [snip] > modprobe ip_nat_ftp >> # STATE RELATED for router >> iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT >> >> # Localhost >> iptables -A INPUT -i lo -j ACCEPT >> iptables -A OUTPUT -o lo -j ACCEPT >> >> # Open ports on router for server/services #iptables -A INPUT -s 1.2.3.4 -j ACCEPT -p tcp --dport 20 -m state >> --state NEW >> iptables -A INPUT -s 1.2.3.4 -j ACCEPT -p tcp --dport 21 -m state >> --state NEW >> iptables -A INPUT -s 1.2.3.4 -j ACCEPT -p tcp --dport 22 -m state >> --state NEW >> iptables -A INPUT -j ACCEPT -p tcp --dport 25 -m state --state NEW >> iptables -A INPUT -j ACCEPT -p tcp --dport 80 -m state --state NEW >> iptables -A INPUT -j ACCEPT -p tcp --dport 143 -m state --state NEW >> iptables -A INPUT -j ACCEPT -p tcp --dport 993 -m state --state NEW