You create a MySQL DB system with default port numbers, and attach it to a...

To enable client applications to connect to a MySQL DB system that uses default port numbers and is attached to a subnet, you need tocreate an ingress rule that allows stateful connections on port 3306 and 33060(Answer C).

Ingress Rule: An ingress rule specifies the types of inbound connections that are allowed to a resource within a subnet.

Stateful Connections: Stateful connections keep track of the state of network connections passing through them, allowing return traffic to pass automatically.

Steps:

Navigate to the Virtual Cloud Network (VCN) in the OCI Console.

Open the subnet to which the MySQL DB system is attached.

Add an ingress rule to the subnet's security list to allow traffic on port 3306 (MySQL) and 33060 (MySQL X Protocol).

Ensure the rule is stateful to maintain the connection state.

References:

OCI Networking Documentation

MySQL X Protocol Documentation