srinivasmohan

#!/bin/bash

# Configure the instance to run as a Port Address Translator (PAT) to provide 
# Internet connectivity to private instances. 
# This is pretty much the same as the configure-pat.sh script from a AWS AmazonLinux NAT instance except that we tweak 
#the iptables rule to NOT NAT traffic that has to flow over the VPN but NAT anything that does'nt match our remote ends 
#VPC CIDR value. This way access to remote subnet over VPN will be normally routed and not NATted to IP of our NAT instance.
#E.g. in this script, the assumption is that the VPC CIDR for the "other" end is 172.19.0.0/16. YMMV.
#See http://www.onepwr.org/2012/08/20/link-amazon-vpcs-over-a-ipsec-site-to-site-vpn/ for full atricle.
# Srinivas - 20120820.

liamf

#################################################################################
# Import modules
#################################################################################

import os
import time
import sys
import socket
import string