error indicates that clients cannot reach the Dynamic Data Masking listener port.
If you receive this error, verify that the firewall configuration has the Dynamic Data Masking listener port and administrator port open. For example, the default Dynamic Data Masking listener port for Oracle is 1525 and the default administrator port is 8195.
The
TNS: No Listener
error is an error for connections to Oracle databases. A similar error might appear for a different database.