From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tom" Subject: Problem for Bittorrent Application behind Linux Firewall Date: Tue, 23 Sep 2003 17:16:41 +0800 Sender: netfilter-admin@lists.netfilter.org Message-ID: <049201c381b3$672939f0$5a01a8c0@wireless.cheung.com> Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_048F_01C381F6.74CDAD00" Return-path: Errors-To: netfilter-admin@lists.netfilter.org List-Help: List-Post: List-Subscribe: , List-Id: List-Unsubscribe: , List-Archive: To: netfilter@lists.netfilter.org This is a multi-part message in MIME format. ------=_NextPart_000_048F_01C381F6.74CDAD00 Content-Type: text/plain; charset="big5" Content-Transfer-Encoding: quoted-printable Hello Everyone: I have encountered a problem when implementing my Linux Firewall using = iptables together with some applications like Bittorrent.It's peer to = peer application sharing program.My Linux have two network interfaces, = one is connecting to my internal LAN with IP range 192.168.1.0/24 and = other network interface is connecting to internet via ADSL modem using = PPPoE. Before I illustrated my situation to you, I have tried to use "BT = client" called Bittorrent S-5.7.3(Shadow's Experimental) to download = file from the others. It has no problem for download but the light turns = "YELLOW" to indicate that I'm behind firewall.Then I add some rules to = my iptables to allow traffic can pass via in my machines in LAN from = outside. The following is my iptables rules.According to my understanding, BT use = the ports 6881 to 6889,Then I forward these ports to my machines in LAN. #! /bin/sh iptables -t nat -A PREROUTING -i ppp0 -p tcp --dport 6881:6889 -j DNAT = --to 192.168.1.90:6881-6889 iptables -A FORWARD -p tcp -s 192.168.1.90 --dport 6881:6889 -j ACCEPT After I have implemented these rules, my light for BT client turns to = "GREEN" mean that it's operational.Then I try to make some BT file for = someone to download behind firewall, but problem occurs. The light is = always "RED" - there are no connections from other clients. So I would like to know that what happens to my linux firewall and how = can I do to achieve my goal that creating BT files behind firewall for = others to download ? The above chain rules already prove that outside traffic can come in to = my client machine. I appreciate if anyone can help me to solve these problems...many thx !! Tom Cheung 23 Sept 2003 ------=_NextPart_000_048F_01C381F6.74CDAD00 Content-Type: text/html; charset="big5" Content-Transfer-Encoding: quoted-printable
Hello Everyone:
 
I have encountered a problem = when=20 implementing my Linux Firewall using iptables together with some = applications=20 like Bittorrent.It's peer to peer application sharing program.My Linux = have two=20 network interfaces, one is connecting to my internal LAN with IP range=20 192.168.1.0/24 and other network interface is connecting to internet via = ADSL=20 modem using PPPoE.
 
Before I = illustrated=20 my situation to you, I have tried to use "BT client" called Bittorrent=20 S-5.7.3(Shadow's Experimental) to download file from the = others. It=20 has no problem for download but the light turns "YELLOW" to indicate = that I'm=20 behind firewall.Then I add some rules to my iptables to allow traffic = can pass=20 via in my machines in LAN from outside.
 
The following is my=20 iptables rules.According to my understanding, BT use the ports 6881 = to=20 6889,Then I forward these ports to my machines in LAN.
 
#! /bin/sh
iptables -t nat -A PREROUTING -i = ppp0 -p tcp=20 --dport 6881:6889 -j DNAT --to 192.168.1.90:6881-6889
iptables -A FORWARD -p tcp -s = 192.168.1.90=20 --dport 6881:6889 -j ACCEPT
 
After I have implemented these = rules, my=20 light for BT client turns to "GREEN" mean that it's operational.Then I = try to=20 make some BT file for someone to download behind firewall, but problem = occurs.=20 The light is always "RED" - there are no connections from other=20 clients.
 
So I would like to know that = what happens=20 to my linux firewall and how can I do to achieve my goal that creating = BT files=20 behind firewall for others to download ?
 
The above chain rules already = prove that=20 outside traffic can come in to my client machine.
 
I appreciate if anyone can help = me to solve=20 these problems...many thx !!
 
Tom Cheung
23 Sept = 2003
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