Hi folks, I have some ambitious plans to set up a Fedora Core 5 node as a transparent bridge between my host's gateway and the remainder of a rack of nodes colocated at the host that I share with some friends. I've had a hard time getting this working. I seem to be stuck at a pretty basic level, so I am hoping there is something obvious someone can point out for me. For example, I just noticed one warning against using 2.6 kernels. Is that still true, even for the most current 2.6 kernels (2.6.16.1)? I'd like to start with a very simple question: what is the minimal steps to set up a server with two ethernet interfaces (eth0 and eth1) as a transparent bridge? I'm following the Nils Radtke's how-to here: http://www.tldp.org/HOWTO/Ethernet-Bridge-netfilter-HOWTO.html Assume I have a 3 node network: L:eth0 <-> eth0:B:eth1 <-> eth0:R B is my bridge. L and R are nodes on the same subnet that can ping each other if the bridge is replace by a hub. From what I know so far, I thought the following steps on the bridge should be enough: 1) remove all iptable rules. 2) do the following (ifdown eth0 1>/dev/null 2>&1;); (ifdown eth1 1>/dev/null 2>&1;); brctl addbr br0; brctl stp br0 on; brctl addif br0 eth0; brctl addif br0 eth1; ifconfig eth0 0.0.0.0 up; ifconfig eth1 0.0.0.0 up; ifconfig br0 up The above commands are taken from <http://www.tldp.org/HOWTO/Ethernet- Bridge-netfilter-HOWTO-3.html#ss3.3>, but reordered and stripped down. Note in particular I don't assign the br0 interface an ip address. After doing the above, should I be able to once again ping R from L and vice versa? Or is setting proxy_arp and forwarding required? for file in br0 eth0 eth1; do echo "1" > /proc/sys/net/ipv4/conf/${file}/proxy_arp; echo "1" > /proc/sys/net/ipv4/conf/${file}/forwarding; done; echo "1" > /proc/sys/net/ipv4/ip_forward; From reading Nils's how-to, these steps seem to be necessary. However, the bridge wiki page doesn't mention them <http://linux- net.osdl.org/index.php/Bridge>, and another page makes it seem like they might only be necessary for "pseduo-bridges": <http://lartc.org/ howto/lartc.bridging.proxy-arp.html>. Thanks in advance for any answers. Jim Lloyd
