3.3.3. ExpressRoute Features
Global Reach: Connects two ExpressRoute circuits, enabling on-premises-to-on-premises traffic through Microsoft's backbone. Example: Connect your New York datacenter to your London datacenter via Azure's network instead of the public internet.
FastPath: Bypasses the ExpressRoute Gateway for traffic destined to VNets, reducing latency by ~1-2ms. Supported on Ultra Performance and ErGw3AZ gateway SKUs only. Traffic still requires the gateway for network features like VNet peering—FastPath only optimizes direct VM access.
BFD (Bidirectional Forwarding Detection): Detects link failures in sub-second timeframes (vs. BGP's default 180-second hold timer). Enable on your CE router for faster failover.
MACsec (ExpressRoute Direct only): Layer 2 encryption between your router and Microsoft's edge. Encrypts all traffic on the physical link, not just at the IP layer.
