Azure Route Server is the specific service designed to simplify dynamic routing between Network

Virtual Appliances (NVAs), such as the FortiGate VMs, and the Azure virtual network. It facilitates

the exchange of routing information via the Border Gateway Protocol (BGP) between the NVA and

the Azure Software Defined Network (SDN). This allows the FortiGate VMs to automatically learn

routes from the Azure VPN and ExpressRoute gateways and advertise routes back to them,

eliminating the need for complex, manually configured User-Defined Routes (UDRs). This directly

addresses the requirement to centralize and simplify dynamic route sharing in the described

hub-and-spoke topology.

B. Azure Traffic Manager: This is a DNS-based traffic load balancer that operates at the

application layer, not a network-level service for exchanging BGP routes.

C. Azure Virtual Hub: This is a Microsoft-managed virtual network component within an Azure

Virtual WAN, not the specific service that enables BGP peering with an NVA.

D. Azure Virtual WAN: This is a comprehensive networking service for building large-scale,

unified hub-and-spoke architectures, not the specific mechanism for NVA route exchange.

1. Microsoft Azure Documentation, "What is Azure Route Server?": "Azure Route Server

simplifies dynamic routing between your network virtual appliance (NVA) and your virtual network.

It allows you to exchange routing information directly through Border Gateway Protocol (BGP)

routing protocol between any NVA that supports the BGP routing protocol and the Azure Software

Defined Network (SDN) in the Azure Virtual Network (VNet) without the need to manually

configure or maintain route tables."

URL: https://learn.microsoft.com/en-us/azure/route-server/overview

2. Fortinet Documentation, "FortiGate-VM on Azure > Azure Route Server integration": This

official guide details the integration of FortiGate-VM with Azure Route Server. It states the

purpose is to "dynamically exchange routing information with other resources in the VNet," which

includes learning routes from and advertising routes to Azure gateways.

URL: https://docs.fortinet.com/document/fortigate-public-cloud/7.4.0/azure-administration-guide/5

85830/azure-route-server-integration

3. Microsoft Azure Documentation, "Azure Route Server FAQ": In response to whether Route

Server supports route advertisement to ExpressRoute and VPN, the documentation confirms:

"Yes. If you peer your NVA with Azure Route Server, it'll advertise the routes it learns from the

NVA to ExpressRoute and VPN Gateway."

URL: https://learn.microsoft.com/en-us/azure/route-server/route-server-faq (Section:

Functionality)