From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chris Hoeschen" Subject: RE: Mangling problem Date: Wed, 21 May 2003 08:26:44 -0500 Sender: netfilter-admin@lists.netfilter.org Message-ID: <06f501c31f9c$9f34e930$7035a8c0@hoeschen> References: <000001c31f8f$1866f1d0$88cc858b@TOSHIBAFIRE> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <000001c31f8f$1866f1d0$88cc858b@TOSHIBAFIRE> Errors-To: netfilter-admin@lists.netfilter.org List-Help: List-Post: List-Subscribe: , List-Id: List-Unsubscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii" To: 'Regina Reine' Cc: netfilter@lists.netfilter.org I maybe wrong but I don't believe netfilter will process any packets not intended for that box. TCPDump will see it as in a hubbed environment all nodes receive all packets but only those that are destined for that box will netfilter process. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- | Chris Hoeschen - Distributed System Analysts | | PrimeVest Financial Services | | (320) 656-4035 E-Mail: chris.hoeschen@primevest.com | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." -- Albert Einstein Hippopotomonstrosesquippedaliophobia is the fear of long words -----Original Message----- From: netfilter-admin@lists.netfilter.org [mailto:netfilter-admin@lists.netfilter.org] On Behalf Of Regina Reine Sent: Wednesday, May 21, 2003 6:50 AM To: netfilter@lists.netfilter.org Subject: Mangling problem Hi, I am doing an experiment with iptables. I use a hub to connect two computers. Computer A captures the video packet (or any packets) and computer B runs iptables and my code in Red Hat 8. Basically, with hub, computer B will be able to see the packets coming to computer A. I would like computer B to preroute this packet and put these packets in userspace where I run my code. I uses : ** Iptables -t mangle -I PREROUTING -p udp -I eth0 -j QUEUE However, seems like I only be able to capture broadcast packets. (But TCPDUMP could see the udp packets). I have checked my code (just a simple code that scan what kind of packets and it worked with udp generator such as iperf or hping). I have tried a few other similar ways but still only could capture broadcast packets. Does anybody spots my mistake or could give me advice for better solution? Thank you Best regards, Regina Reine