Openswan connection for us-east

eastwest.conf

#See http://www.onepwr.org/2012/08/20/link-amazon-vpcs-over-a-ipsec-site-to-site-vpn/ for full atricle.
#This is the config for the US-East Openswan. For the west side openswan config, swap the left and right values accordingly.
conn eastwest
  authby=secret
  auto=start
  type=tunnel
  #Left is "this" side
  left=172.18.0.254
  leftid=4.5.6.7
  leftsubnet=172.18.0.0/16
  #Right is the other side i.e. us-west so right and rightsubnet become Elastic IP of us-west
  #NAT instance and the VPC CIDR for the us-west VPC
  right=1.2.3.4
  rightsubnet=172.19.0.0/16
  ike=aes256-sha1;modp2048
  phase2=esp
  phase2alg=aes256-sha1;modp2048
  forceencaps=yes