Physical Data Center Network Transformation to Microsoft Azure IaaS Hub-and-Spoke Architecture for Ryan Specialty

Abstract

Enterprise migration from traditional physical data centers to public-cloud infrastructure requires fundamental changes to network architecture. Physical switching, routing, firewalling, segmentation, and connectivity constructs must be translated into software-defined cloud services while preserving application availability, security boundaries, routing control, and enterprise connectivity.

Ryan Specialty initiated a transformation of its on-premises physical data center network into Microsoft Azure Infrastructure as a Service (IaaS) using a standardized Hub-and-Spoke network architecture. The objective was to modernize infrastructure, improve scalability, centralize network and security controls, segment application workloads, and provide seamless connectivity between Azure-hosted resources and the broader enterprise environment.

As a Senior Principal Consultant with Genpact, Srinivas Marka contributed to the architecture and implementation of the Azure network foundation, including virtual network design, hub-and-spoke topology, IP address planning, subnet segmentation, routing, hybrid connectivity, security integration, workload migration planning, and production validation.

The working program scope encompassed approximately 30+ Azure Virtual Networks (VNets), 100+ subnets, 500+ routing and security-policy relationships, 150+ application/server workloads, two Azure regions, and more than 5,000 enterprise users and connected endpoints. More than 750 technical and application validation checks were performed throughout migration waves.

The resulting architecture replaced significant portions of traditional physical data center network functionality with a centralized, scalable, software-defined Azure networking model and established a foundation for continued cloud adoption at Ryan Specialty.