lxc-network-bridge-nat

#!/bin/sh
# startup script for starting a network bridge and initialize a
# private network that will use the node as its gateway with NAT.
# connections coming from the outside on the main node
# can be redirected on the internal containers using iptables.
# if you want it to start at boot, you can add it like this
# to /etc/rc.d/rc.local
#
# # start a bridge used by lxc containers
# if [ -x /usr/local/sbin/lxc-network-bridge-nat ]; then
#    /usr/local/sbin/lxc-network-bridge-nat
# fi

/sbin/brctl addbr br0
/sbin/brctl setfd br0 0
/sbin/ifconfig br0 192.168.11.1 netmask 255.255.255.0 promisc up
echo 1 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/conf/br0/proxy_arp
/usr/sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

# examples of redirections
iptables -t nat -A PREROUTING -p tcp --dport 51 -i eth0 -j DNAT --to 192.168.11.2:51
iptables -t nat -A PREROUTING -p tcp --dport 80 -i eth0 -j DNAT --to 192.168.11.3:80