You are using access rules to control network traffic among your DBaaS instances.
Which statement is true about access rules?
A.
They are used only for configuring external server access to DBaaS and do not impact how network groups communicate.
B.
They define a specific communication path, which consists of a source, destination, and protocol-port combination over which communication is allowed.
C.
They are used to map an external user to a database user to allow the user to communicate with and access the database.
D.
They are used to encrypt communication between DBaaS instances.
Explanation:
On the Access Rule you can define the following:
Source
Hosts from which traffic is allowed. Possible values are DB, PUBLIC-INTERNET, or a custom value in the form of an IP address.
Destination
Security list to which traffic is allowed. This will be DB, the ora_db security list for the deployment.
Ports
Port or range of ports for the rule.
https://docs.oracle.com/en/cloud/paas/database-dbaas-cloud/csdbi/service-console-access-rules-page.html