Changes

In addition, to make some services in VPS with internal IP address be accessible from the Internet, DNAT (Destination Network Address Translation) should be configured on the Hardware Node. To perform a simple DNAT setup, execute the following command on the Hardware Node:

# iptables -t nat -A PREROUTING -p tcp -d ip_address --port port_num -i eth0 -j DNAT --to-destination vps_address:dst_port_num

where vps_address is an IP address of VPS, dst_port_num is a tcp port, which required service use, ip_address is the external IP address of your Hardware Node, and port_num is a tcp port of Hardware Node, which will be used for Internet connections to private VPS service. Note that this setup makes the service, which use port_num on the Hardware Node, be unaccessible from the Internet. Also note that SNAT translation is required too.