The Networking service in Oracle Cloud Infrastructure (OCI) offers two virtual firewall features to control traffic at the packet level: network security groups and security lists.

• Network security groups (NSGs): Act as a virtual firewall for OCI resources such as Oracle Analytics Cloud. An NSG consists of a set of ingress and egress security rules that apply only to a set of VNICs of your choice in a single VCN. To learn more about NSGs and how to manage ingress and egress security rules, see Network Security Groups.
• Security lists: The original type of virtual firewall offered by the Networking service. See Security Lists.

Either option or a combination of these two features can be used. See Comparison of Security Lists and Network Security Groups .