Hi all, I am currently using iptablesv1.3.5 on fedora core 5. At this point I am just playing around and trying to learn the system, but my general idea is to setup my linux box as a bridge. Ultimatly I then plan on using firewalling to redirect/drop whatever traffic is deemed worthy. So I have linux setup correctly as a bridge as so: br0 : inet addr - 172.20.134.7 eth0 and eth1 are unaddressed and part of the bridge. I set this up as follows: sudo ifdown eth1 sudo ifdown eth1 sudo ifconfig eth0 0.0.0.0 sudo ifconfig eth1 0.0.0.0 sudo brctl addbr "br0" sudo brctl setfd br0 0 sudo brctl addif br0 eth1 sudo brctl addif br0 eth0 sudo ifup br0 sudo ifconfig br0 172.20.134.7 netmask 255.255.0.0 sudo ip route add default 172.20.255.254 Now my problem with iptable is the following: I tried to setup a rule to look for ICMP from a particular interface as such. iptables -t filter -A FORWARD -p icmp -i eth0 iptables -t filter -A FORWARD -p icmp -i eth1 iptables -t filter -A FORWARD -p icmp -i br0 Now, the only filter that ever matches any packets is br0. So because of the way the bridge works, if I can't use eth0 or eth1 as input/output interfaces, then I can't really tell 'direction' of traffic between my lan and my wan. Is there something I am missing here? I would assume there is a way to do this (tell direction over bridge) but I don't know what it is.... so any help or pointers would be greatly appreciated. Thanks, Brian
