I am running the load balancer for ec2 machines and there is separate Aurora RDS is running. They both are in same region. I want to open rds default port only for aws classic load balancer. I am can't find the option in security group and there is no IP for load balancer for which I can open port for RDS. Please help me to resolve this issue. I want to open the port of RDS only for my loadbalacer not for all in RDS security group. Can someone please help to resolve this issue? Thanks
Solution of this problem is to specify the security group id of you ec2 machines in RDS inbound security rule. Thanks @MarkB