Optimal routing with ExpressRoute – Revisited

This article revisits optimal routing configurations for Azure ExpressRoute, addressing challenges in mapping older documentation to current Virtual WAN (VWAN) technologies. It discusses key VWAN improvements such as secured hubs for easy firewall deployment and route maps for traffic engineering, which help prevent asymmetric routing issues. The article explains architectural patterns for connecting on-premises data centers to Azure regions using ExpressRoute circuits, including standard, premium, and local circuit types, and explores design tensions between circuit location alignment and data center proximity. It provides guidance for modern network designs in Azure.