Generally Available: ExpressRoute FastPath Support for Vnet Peering & UDR

We are announcing support for ExpressRoute FastPath VNet Peering and User Defined Routes (UDR) connectivity. This feature enhances data path performance between on-premises customer networks and Azure Virtual Networks. It unlocks 100Gbps connectivity to VMs deployed in hub and spoke designs over ExpressRoute.

When FastPath is enabled, it enhances data path performance, and instead of routing through the gateway, FastPath sends network traffic directly to virtual machines within the virtual network, reducing the number of hops and potential bottlenecks. FastPath still requires a virtual network gateway to be created to exchange routes between the virtual network and on-premises network. 

With Virtual Network Peering and User Defined Routes (UDR) support, FastPath will send traffic directly to VMs deployed in "spoke" virtual networks (connected via Virtual Network Peering) and honor any UDRs configured on the Gateway Subnet. FastPath support for virtual network peering and UDRs is only supported for ExpressRoute Direct connections.

Learn more.