auto lo
iface lo inet loopback

iface eth0 inet manual

auto vmbr0
iface vmbr0 inet static
        address  136.243.61.141
        netmask  255.255.255.192
        gateway  136.243.61.129
        bridge_ports eth0
        bridge_stp off
        bridge_fd 0

auto vmbr2
iface vmbr2 inet static
        address  10.21.21.254
        netmask  255.255.255.0
        bridge_ports none
        bridge_stp off
        bridge_fd 0
        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up iptables -t nat -A POSTROUTING -s '10.21.21.0/24' -o vmbr0 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s '10.21.21.0/24' -o vmbr0 -j MASQUERADE
        post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 2222 -j DNAT --to 10.21.21.5:22
        post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 2222 -j DNAT --to 10.21.21.5:22