Improving data path performance with ExpressRoute FastPath
The FastPath feature of ExpressRoute is designed to improve data path performance between connected remote networks and Azure VNets. To understand how the FastPath feature works, we need to understand the default behavior without it.
By default, the ExpressRoute gateway performs two main tasks—exchanging network routes with our remote networks AND routing network traffic to Azure VNet resources (Figure 6.22). Routing the network traffic adds a little processing overhead, which impacts performance metrics such as packets per second (PPS) and connections per second (CPS):
Figure 6.22 – Traffic routing without FastPath
When enabled, FastPath sends network traffic directly to VNet resources, bypassing the gateway (Figure 6.23). This results in higher throughput and overall better performance!
FastPath is available for all ExpressRoute circuits, but the ExpressRoute gateway must...