I am hosting my website on 3 amazon instances but I cannot connect them together. I am using windows server 2008 and when I ping xxxxxxxxxxxxxxx.compute-1.amazonaws.com, I get request timed out. Using IP address also doesn't help. Also should I use IP or xxxxxxxxxxxxxxx.compute-1.amazonaws.com address to access each other. Thanks
You have to permit pinging (and any other incoming traffic you want to allow) in your AWS EC2 security groups. You should always use the instance CNAMEs, as the IPs can change.