Amazon Redshift cluster security groups

When you provision an Amazon Redshift cluster, it is locked down by default so nobody has access to it. To grant other users inbound access to an Amazon Redshift cluster, you associate the cluster with a security group. If you are on the EC2-VPC platform, you can either use an existing Amazon VPC security group or define a new one and then associate it with a cluster. For more information on managing a cluster on the EC2-VPC platform, see Managing clusters in a VPC.