What is Azure Route Server?
Azure Route Server is a fully managed service that enables dynamic routing between Network Virtual Appliances (NVAs) and Azure Virtual Networks via BGP (Border Gateway Protocol). It eliminates the need for manually configuring User-Defined Routes (UDRs) in network topologies with changing routes.
Traditionally, routes to NVAs (firewalls, SD-WAN appliances) must be manually configured and maintained via UDRs. Route Server instead acts as a BGP route reflector within the virtual network: NVAs peer with Route Server via BGP, which automatically programs learned routes into the Azure Software Defined Network and advertises virtual network prefixes back to the NVAs.
Route Server is highly available thanks to the underlying managed Azure infrastructure and currently supports up to 16 BGP peers per Route Server. Branch-to-branch routing also allows connecting ExpressRoute connections and VPN Gateway through NVAs.
Core Features
Dynamic route exchange: Automatic exchange of routes between NVAs and Azure networks using the BGP standard.
Simplified routing management: Eliminates manual route table maintenance when the network topology changes.
Support for multiple NVAs: Connect multiple NVA instances with configurable BGP attributes for active-active or active-passive scenarios.
Standards-based integration: Works with any NVA that supports BGP, regardless of vendor.
Integration with ExpressRoute and VPN Gateway: Exchange routes between ExpressRoute circuits, VPN connections, and NVAs for hybrid connectivity.
Typical Use Cases
SD-WAN integration: SD-WAN appliances peer with Route Server. Branch office routes are automatically propagated to Azure VNets without manually maintaining UDRs.
Third-party firewall routing: Next-generation firewalls dynamically receive routes to spoke VNets. New spokes are automatically routed through the firewall.
Hub-spoke with dynamic routes: In hub-spoke topologies, Route Server automatically propagates routes between spokes without manual UDR maintenance for new spokes.
Hybrid transit: Connecting ExpressRoute sites with VPN branches via NVAs in the hub, including intelligent path selection and failover between connectivity types.
Benefits
- Significantly reduced administrative effort compared to manual UDR maintenance
- Support for multiple NVA instances for high-availability scenarios
- Vendor-agnostic as long as the NVA supports BGP
- Simple, hourly pricing model with no separate data processing fees
Frequently Asked Questions about Azure Route Server
What is the difference to Azure Firewall or Virtual WAN?
Route Server is dedicated exclusively to dynamic routing via BGP and offers no firewall or full WAN functionality. It complements NVAs with automated route exchange. Azure Virtual WAN provides a more comprehensive, managed WAN solution including routing. Route Server is suited for custom hub-spoke setups with third-party NVAs.
How many BGP peers are supported?
Currently up to 16 BGP peers per Route Server, with a limit of 4,000 routes that each peer can advertise. Exact limits can change; current values are available in the official documentation.
Can Route Server filter routes?
Route Server is primarily designed to propagate learned routes; fine-grained filtering is typically performed on the NVA side (e.g., via BGP route maps or prefix lists).
What does Azure Route Server cost?
Billing is hourly for the deployment of the Route Server, regardless of data volume; there are no additional costs for processed routes or BGP sessions. Current prices are available on the official pricing page.
Is Route Server highly available?
Yes, Route Server runs on managed, redundant Azure infrastructure with built-in fault tolerance.
Integration with innFactory
As a Microsoft Solutions Partner, innFactory supports you in implementing Azure Route Server for complex network topologies. We help with SD-WAN integration, NVA configuration, and hybrid network design.
Contact us for a non-binding consultation on Azure Route Server and enterprise networking.
Typical Use Cases
Note: All product information on this page has been compiled with care, but is provided without guarantee and may be outdated or incomplete. Cloud services evolve rapidly — features, pricing, SLAs, and availability change frequently. Authoritative and up-to-date information can only be found on the official product page of Azure (official documentation). This page does not represent an offer by Azure.
