A year and half ago I was somewhat lazy to read the whole documentation and, consequently, made something which turned to be something which I am not able to reproduce. (Last months I''ve configured network regularly.) My need was relatively simple: I have one (in that case, two) public networks routed via the dom0 to domUs. I didn''t want to make xen bridges and it worked. I suppose that it''s not anything new, and I would really like to repeat it. The point is that that approach makes network configuration simpler. So, here are the general data about the system, then goes relevant configuration: * Debian Squeeze * Kernel 2.6.32-5-xen-amd64 * Xen: xen-hypervisor-4.0-amd64 /etc/network/interfaces # Loopback device: auto lo iface lo inet loopback # device: eth0 auto eth0 iface eth0 inet static address A.B.C.194 broadcast ... netmask 255.255.255.224 gateway ... auto eth0:1 iface eth0:1 inet static address A.B.C.1 broadcast A.B.C.15 netmask 255.255.255.248 auto eth0:2 iface eth0:2 inet static address A.B.C.17 broadcast A.B.C.31 netmask 255.255.255.248 # default route to access subnet up route add -net A.B.C.192 netmask 255.255.255.224 gw A.B.C.193 eth0 * * * /etc/xen/xend-config.sxp (network-script network-bridge) (vif-script vif-bridge) (network-script network-route) (vif-script vif-route) (dom0-min-mem 196) (enable-dom0-ballooning yes) (total_available_memory 0) (dom0-cpus 0) (vncpasswd '''') # yes, didn''t bother to configure it :) * * * /etc/rc.local (instead of /etc/sysctl.conf) echo 1 > /proc/sys/net/ipv4/ip_forward echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp * * * one of the domUs files (relevant part): vif = [ ''ip=A.B.C.D,mac=AA:BB:CC:DD:EE:FF,bridge=eth0'' ] * * * Note: I am not able to find masquerading command. It would be in /etc/rc.local, but nothing is there. My concept was that if Xen bridges network and I have ip_forward and proxy_arp configured, domUs will act as they are on the same LAN/ethernet. In that particular case I was right. However, as I said it above, I didn''t succeed in repeating it. Any idea?