Hi Marwan, I remember libvirt has a similar bug, but I forgot bug number, Laine can help confirm this, could you provide your libvirt version? thanks. -- Regards, Alex ----- Original Message ----- From: "Marwan Tanager" <marwan.tngr(a)gmail.com&gt; To: libvirt-users(a)redhat.com Sent: Wednesday, September 26, 2012 11:18:35 AM Subject: [libvirt-users] Inconsistent iptables forwarding rules for virtual networks? Hi everyone. Those are the iptables forwarding rules associated with the two virtual networks on my machine: ----------------------------------------------------------------------------------------- -A FORWARD -d 192.168.100.0/24 -o virbr1 -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -s 192.168.100.0/24 -i virbr1 -j ACCEPT -A FORWARD -i virbr1 -o virbr1 -j ACCEPT -A FORWARD -o virbr1 -j REJECT --reject-with icmp-port-unreachable -A FORWARD -i virbr1 -j REJECT --reject-with icmp-port-unreachable -A FORWARD -d 192.168.122.0/24 -o virbr0 -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -s 192.168.122.0/24 -i virbr0 -j ACCEPT -A FORWARD -i virbr0 -o virbr0 -j ACCEPT -A FORWARD -o virbr0 -j REJECT --reject-with icmp-port-unreachable -A FORWARD -i virbr0 -j REJECT --reject-with icmp-port-unreachable ----------------------------------------------------------------------------------------- Using this setup I can ping from a guest on 192.168.100.0/24 to a guest on 192.168.122.0/24, however the reverse is not possible (I get 'port unreachable' icmp messages). This is caused by the fourth rule, which rejects packets forwarded to virbr1. Moving the fourth rule to the end, obviously eliminates this problem. So, is this default setup intentional for some reason, or should the rules just be rearranged by libvirt, so that any rule on the FORWARD chain which has a REJECT target (which reject forwarding "to" some virtual interface) would go to the end of the chain, and thus, allowing the virtual networks to reach each other by default? Thanks. Marwan _______________________________________________ libvirt-users mailing list libvirt-users(a)redhat.com https://www.redhat.com/mailman/listinfo/libvirt-users