title: RDS Security Groups Ingress rule
body: <p>I'm working on CloudFormation template which includes RDS Database and I wanted to attach security group to RDS. There is a resource <a href="http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-rds-security-group.html" rel="nofollow">AWS::RDS::DBSecurityGroup</a>  where I would like to write my own Ingress Rules which allows MySQL traffic from the front end instances by attaching this resource <a href="http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-rds-security-group-ingress.html" rel="nofollow">AWS::RDS::DBSecurityGroupIngress</a> but, it doesn't show any properties like "FromPort" , "ToPort" , "Protocol" , etc..</p>
  
  <p>I'm unsure whether the above listed properties will support or not.</p>