interfaces.example

auto lxc-br
iface lxc-br inet static
	address 172.23.0.1/16
	## OUI of PEGATRON CORPORATION is 60:02:92
	## lower two bits of first octet is
	## Global - 0 / Local - 1 bit and Individual - 0 / Group - 1 bit,
	## so 60 + 2 + 0 == 62
	bridge_ports none
	bridge_hw 62:02:92:11:11:01
	bridge_maxwait 0

lxc-config

##
lxc.network.type = veth
lxc.network.flags = up

lxc.network.link = lxc-br

# the ip may be set to 0.0.0.0/24 or skip this line
# if you like to use a dhcp client inside the container
lxc.network.ipv4 = 172.23.0.10/16
lxc.network.ipv4.gateway = 172.23.0.1

nat.sh

#!/bin/sh

cmd="$1"
host_if="$2"

if [ x"$cmd" = x ]; then
	cat<<EOF
Usage: $0 {start|stop} [NAT_INTERFACE]
       $0  show
EOF
	exit 0
fi

start() {
    /sbin/iptables -t nat -A POSTROUTING -o ${host_if} -j MASQUERADE
    /sbin/sysctl -w net.ipv4.ip_forward=1
}

stop() {
    /sbin/sysctl -w net.ipv4.ip_forward=0
    /sbin/iptables -t nat -D POSTROUTING -o ${host_if} -j MASQUERADE
}

set -x

case $cmd in
    show)
        /sbin/sysctl net.ipv4.ip_forward
        /sbin/iptables -t nat -L -v
        ;;
    start|stop)
        if [ x"$host_if" = x ]; then
            for i in eth0 ; do
                host_if=$i
                $cmd
            done
        else
            $cmd
        fi
        ;;
    *)
        echo "Unknown command: $cmd"
        exit 1
        ;;
esac