No internet connection from guests

[Ventzy]

I have simple situation, but I could not get it to work.

I have one machine with Proxmox 3.1.
I have public static IP address and Proxmox host have internet connection (ping google.com works).
I need few VMs (OpenVZ, Ubuntu Server 12) which needs to connection to internet and have IP addresses like 10.0.0.XXX

Network configuartion on the host

auto lo
iface lo inet loopback


auto eth0
iface eth0 inet static
        address  MY_PUBLIC_IP
        netmask  255.255.255.240
        gateway  MY_PUBLIC_GATEWAY
        post-up echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp




auto vmbr0
iface vmbr0 inet static
        address  10.0.0.1
        netmask  255.255.255.0
        bridge_ports none
        bridge_stp off
        bridge_fd 0

At VM creation I have tried both options - "Routed mode (venet)" with IP 10.0.0.2 and "Bridged mode" with vmbr0. In both cases, there is no ping to MY_PUBLIC_GATEWAY from VM. What is missing?

 

[Ventzy]

As suspected the solutions is very easy from here http://pve.proxmox.com/wiki/Network_Model#Masquerading

I added following lines at the end of host's /etc/network/interfaces

        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up   iptables -t nat -A POSTROUTING -s '10.0.0.0/24' -o eth0 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s '10.0.0.0/24' -o eth0 -j MASQUERADE