----- Original Message ----- > From: "Phil Daws" <uxbod@xxxxxxxxxxxx> > To: kvm@xxxxxxxxxxxxxxx > Sent: Thursday, March 14, 2013 10:53:43 AM > Subject: Virtual Firewall > > 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. This is well supported in libvirt [1] If you don't want to use libvirt then you can at least run to test the rules that are created or look at the code. [1] http://libvirt.org/firewall.html > > 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 > -- 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
