We have a setup where our Load Balancer is talking to one of our RDS instances at Amazon. For the Security Group of our RDS instance we have to fill in a IP Address. Only the IP address of the Load Balancer cant be used because it could change. So we should "create a CNAME record for the Load Balancer DNS name". But we can only fill in a IP address into the Security Groups, so there's the problem.
What should be do to keep it secure but also working? Because opening the RDS instance for all ip addresses doesn't seem safe to me.