ref: 
http://n4jj.x.rootbsd.net:8080/~cpfong/docs/cp_class/ec2-vpn-mac-tunnelblick.txt

0. make no-ip work 1st
1. add udp 1194 into security group
2. sudo yum install -y openvpn (server side)
 cd /etc/openvpn/
 # ls ~/00bsd_my_doc/aws/vpn/00ReadME.txt (step to make openvpn.config.tgz)
 sudo curl -O http://199.102.79.18:8080/tmp/openvpn.config.tgz
 tar xfvz openvpn.config.tgz
 service openvpn start
 cat ./rc.local >> /etc/rc.local
 reboot
 now mac client with connect to server

setup openvpn client 4 windows (4 steps)
--
download software from here:
http://help.unotelly.com/support/articles/184301-openvpn-desktop-client-setup-windows-

Step 1: Download and Install the OpenVPN Desktop Client
Step 2: Download OpenVPN Config File
Step 3: Add OpenVPN Configuration File to the Desktop Client
Step 4: Connect to YourNewVPNServer


setup tunnelblick vpn client 4 mac
--
scp ec2-user@vpn.mic.ifong.org:~/new-vpn.key .
install tunnelblick.config
now client vpn UP

-- client config @ mac
dev tun
proto udp
remote vpn.cp.ifong.org 1194
resolv-retry infinite
nobind
secret openvpn-key.txt
ifconfig 192.168.2.2 192.168.2.1
comp-lzo
verb 3
dhcp-option DNS 8.8.8.8
redirect-gateway def1