Explanation/Reference:
To enable access to a compute node port, you enable the appropriate security rule. When you enable one of the predefined security rules, the given port on the compute node is opened to the public internet. To enable access to a different port, or restrict access to a port, you must create a security rule.
Note: When a database deployment is created, the following Oracle Compute Cloud Service security rules are created, but set to a disabled status.
ora_p2_dbconsole, which controls access to port 1158, the port used by Enterprise Manager 11g

Database Control.
ora_p2_dbexpress, which controls access to port 5500, the port used by Enterprise Manager Database

Express 12c.
ora_p2_dblistener, which controls access to the port used by SQL*Net.

ora_p2_http, which controls access to port 80, the port used for HTTP connections.

ora_p2_httpssl, which controls access to port 443, the port used for HTTPS connections, including

Oracle REST Data Services, Oracle Application Express, and Oracle DBaaS Monitor.
References: References: Using Oracle Database Cloud Service (February 2017), page 3-7
https://docs.oracle.com/en/cloud/paas/database-dbaas-cloud/csdbi/using-oracle-database-cloud- service.pdf