What is the default port for Oracle Database connections?

What is the default port for Oracle Database connections?

• A. 1433
• B. 1521
• C. 1900
• D. 1812

Answer: (B)

The connection to an Oracle database typically goes through the Oracle Net Listener, which by default listens on TCP port 1521. This port is the standard entry point for clients using service names or EZConnect to reach the database, and it must be matched in any connection descriptor (like tnsnames.ora or connect strings). If you change the listener’s port, you must also update those descriptors to point to the new port. The other ports listed correspond to different services: 1433 is commonly used by Microsoft SQL Server, 1900 is used for UPnP device discovery, and 1812 is used for RADIUS authentication. So the default port is 1521.

The connection to an Oracle database typically goes through the Oracle Net Listener, which by default listens on TCP port 1521. This port is the standard entry point for clients using service names or EZConnect to reach the database, and it must be matched in any connection descriptor (like tnsnames.ora or connect strings). If you change the listener’s port, you must also update those descriptors to point to the new port. The other ports listed correspond to different services: 1433 is commonly used by Microsoft SQL Server, 1900 is used for UPnP device discovery, and 1812 is used for RADIUS authentication. So the default port is 1521.