Amazon Redshift
Database Developer Guide (API Version 2012-12-01)

Step 5: Configure the Hosts to Accept All of the Amazon Redshift Cluster's IP Addresses

To allow inbound traffic to the host instances, edit the security group and add one Inbound rule for each Amazon Redshift cluster node. For Type, select SSH with TCP protocol on Port 22. For Source, enter the Amazon Redshift cluster node Private IP addresses you retrieved in Step 3: Retrieve the Amazon Redshift Cluster Public Key and Cluster Node IP Addresses. For information about adding rules to an Amazon EC2 security group, see Authorizing Inbound Traffic for Your Instances in the Amazon EC2 User Guide.