Hello, have been trying to build a virtual firewall as a POC but having some difficulty with the networking aspect. On the physical server I have a single NIC that is connected to the Internet with the IP XXX.XXX.XXX.10 and is bound to bridge0. I created the first guest, as the firewall, and added a virtio interface with source type "Host device vnet (bridge0)". At the guest OS level I assigned the NIC another public IP XXX.XXX.XXX.20 and was able to route quite happily to the Internet. I then proceeded to add a second NIC to the firewall guest but this time using the default NAT network and gave it the address 192.168.1.1. I then created another guest with the IP 192.168.1.2 with its default route being 192.168.1.1 and that could get out to the Internet as-well once the FORWARD+SNAT rules were added to iptables. Now here in lies the problem. I wish to add another network so that I end up with: XXX.XXX.XXX.20 Public Facing 192.168.1.1 Private LAN 192.168.2.1 DMZ So using virtual-manager I created two brand new networks called "PrivateLAN" and "DMZ" with the networks above. I then removed the secondary interface from the firewall and added two new NICs, one being on the PrivateLAN and the other on the DMZ. When I fired up the firewall and attempted to assign those IP addresses to the interfaces the response was: [root@fw1 ~]# ifup eth1 Error, some other host already uses address 192.168.1.1. [root@fw1 ~]# ifup eth2 Error, some other host already uses address 192.168.2.1. Running an arping showed that the MAC for bridge0 already had those IPs registered ?!?!? I am obviously missing a networking fundamental here and really would like some help. If you have only one physical NIC how do you create multiple networks as above; that allows IPtables to control the traffic flow. Any help gratefully appreciated. Thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
