Amazon RDS supports six DB engine types: Amazon Aurora, MySQL, MariaDB, Microsoft SQL Server, Oracle, and PostgreSQL. The following table helps us understand the connecting port and protocol for each of these DB instances:
Amazon RDS engine types | Default port | Protocol |
Aurora DB |
| TCP |
MariaDB |
| TCP |
Microsoft SQL |
| TCP |
MySQL |
| TCP |
Oracle |
| TCP |
PostgreSQL |
| TCP |
The Amazon RDS engine for Microsoft SQL Server and Oracle supports two licensing models: license included and Bring Your Own License (BYOL). In case you are already invested in purchasing licenses for such databases, it can also be used as a BYOL with Amazon RDS to minimize monthly billing.