Designing Transit Routing In Oracle Cloud Infrastructure (Part I)
Oracle, Wednesday, June 4th, 2025
A successful cloud deployment often involves well designed cloud networking that can meet current and future growth in complexity. Connecting various Virtual Cloud Networks (VCNs) and extending them to on-premises or other Cloud providers datacenters are no longer something that good to have, but one of foundational requirements.
By leveraging transit routing, Oracle Cloud Infrastructure (OCI) enables VCN connectivity across regions and customer on-premises.
Recently, I was working on a multi-region OCI setup POC for a customer that required routing traffic between on-premises datacenter and workloads deployed across OCI Phoenix and Chicago regions. The architecture needed to support:
- Hub-and-spoke VCN connectivity in Phoenix region
- Transit routing from on-premises to OCI regions and VCNs
- Future cross-region traffic between OCI Chicago region via Phoenix as a hub
To simplify the configuration with minimal changes at customer's on-premises datacenter, we simulated an on-premises environment, deployed a LibreSwan VPN appliance in Ashburn region and connected it to the Phoenix region via IPSec site-to-site VPN service.