By default, all ports are closed in EC2 until a user opens them up. I would like to keep this behavior but also open up all ports for internal usage (that is, EC2 nodes can communicate with each other on any port but not with the outside world).
The documentation on EC2 security groups does not specify if this is the default behavior or how one would go about doing this. The command line tools provide a way to do this but only if I make each node its own security group and then allow only the groups to talk to each other.
Do you know how I would be able to use the EC2 tools to allow all traffic between nodes in EC2 (or documentation that could help)?