Multi-Availability Domain VCN architecture with IPSec VPN tunnel connecting on-premises networks to OCI, routing traffic through Internet Gateway and VPN Connect. Traffic flows from on-premises through encrypted IPSec tunnel into the VCN, where public subnets in AD1 and AD2 host Load Balancers and Bastion Hosts, while private subnets contain App Server Instances with database replication between Primary and Standby nodes. NAT Gateways in each AD enable outbound connectivity from private subnets, ensuring high availability and disaster recovery across availability domains. This architecture demonstrates OCI best practices for hybrid cloud security, multi-AD redundancy, and network segmentation using public/private route tables. Fork and customize this diagram on Diagrams.so to adapt routing policies, add additional ADs, or modify encryption parameters for your hybrid infrastructure.