Cannot connect to RDS Database instance

You have new RDS DB instance configured, you make sure,

1). The NACL - Network Access control list of configured

2). Security Group is configured

3). Internet Gate way IGC - is added to your VPC

still cannot connect to SQL Server on AWS RDS instance.

4). You have add the route in your route table.

Now you can successfully connect using external ip or dns name on port 1433 for sql server.