title: AWS: How to allow all TCP traffic between all instances in same VPC?
body: <p>I am setting up EMR clusters on demand, and have a windows EC2 server as a workstation, and a linux EC2 server as a secondary server.  All in the same VPC. I would like to avoid having to set security group rules each time an instances comes up with a new IP.</p>
  
  <p>How would I simply allow any traffic to flow freely between all servers in the same VPC?</p>
  
  <p>Thanks!</p>
  
  <p>EDIT-  Thanks for the replies, I know this is not good practice in production, but we are dealing with some issues tracking down functionality which we believe is caused by ports, this is just a exploration phase, and this will help us. Thanks!</p>