AWS RDS Mariadb Federated/Connect

I believe this is a firewall rule problem. Therefore, I believe that the issue is finding out what the public IP address of the RDS is. I don't see that anywhere on the RDS interface. I have two AWS RDS MariaDB databases. I can connect to both without a problem. From the command line, I type: mysql -u me -p db1.cet4jwf1l8xu.us-east-2.rds.amazonaws.com I connect no problem. I can also connect to db2 without a problem. In db2, I want to remotely access a table from db1. I have done this with both Federated and Connect. I get the same error: Can't connect to server, timed out. The syntax for each is pretty much the same: create table testtable engine=federated connection='mysql://me:test@db1.cet4jwf1l8xu.us-east-2.rds.amazonaws.com/mydb/demo'; It sits for a while and then comes up "can't connect." I can switch to engine=connect and get the same timeout error. In the incoming security rules for db1, I have port 3306 open to everywhere. So, I assume it shouldn't be blocking it. Inside db1, user me is set to host '%', which I believe means 'anywhere'. So, I don't think that is the problem either. I'm not sure what else could keep it from connecting when I can connect from a basic CLI on multiple other servers.