Overview
- VCNs regional
- Subnets—can be regional, or scoped to individual Availability Domains (ADs)
Example
![oci_vcn_example](../files/oci_vcn_example.svg)
Firewalls
Security Lists
- Legacy
- Virtual firewalls for compute instances
- Set of ingress and egress rules applied to all VNICs in a subnet
Network Security Groups (NSGs)
- More granular configuration than Security Lists
- Applied to specific VNICs—firewall rules apply only to resources within NSG
Gateways
- Dynamic Routing Gateway
- Transit hub entity
- Interconnect VCNs within a region
- Terminates IPSec VPNs and FastConnect circuits
- Service Gateway
- Allows access to supported Oracle services in the same region as the VCN
- Internet Gateway
- Provides a path for the network traffic between the VCN and the internet
- NAT Gateways
- Allows resources in private subnets to access the internet
Dynamic Routing Gateway (DRG)
- Hub gateway—up to 300 attachments
- Four attachment types:
- VCN attachments
- Remote Peering Connection (RPC) attachments (DRG peering)
- IPSec attachments
- FastConnect attachments
FastConnect
- Private circuit connection to on-prem
- Two types:
- Private peering—access to VCN resources using private IPs
- Public peering—access to public OCI services or public IPs in public subnets