When I tried to use navicat to connect mysql on AWS, it always reject the connection. I'm sure my IP address is correct and the port is correct as I checked on EC2 for several times. Also the username and password are correct too because I can log in mysql on EC2. I don't know what is wrong here. Any help would be really appreciated.
The first thing that will validate is that your instance of aws has active the port to which you want to connect in this case 3306 if it does not work with this you can connect by means of a SSH of the following way remembering that it has to have active the port 22:
host: add the one that EC2 gives you e.g. ec2-127-0-0-1.compute-1.amazonaws.com.
Port: 22.
user: ubuntu or root (or the one indicated in your aws configuration).
Authentication Method: public key.
Private key: your .pem
Connection Name: whatever you want
Host: localhost or 127.0.0.1
Port: 3306
User: the database user
Pass: the database user.
