Merge pull request #284906 from siddomala/EmptyPool

Route Server Troubleshooting for Empty Backend Pool

Author: prmerger-automator[bot]

articles/route-server/troubleshoot-route-server.md

@@ -39,6 +39,10 @@ If you want to inspect your on-premises traffic using a firewall, you can force
 
 Yes, this is expected behavior. User-defined routes with next hop type **Virtual Network Gateway** are not supported for subnets within Route Server's virtual network and peered virtual networks. However, if you want to configure your next hop to be a network virtual appliance (NVA) or the internet, adding a user-defined route with next hop type **VirtualAppliance** or **Internet** is supported. 
 
+### In my VM's network interface's effective routes, why do I have a user-defined route (UDR) with next hop type set to **None**? 
+
+If you advertise a route from your NVA to Route Server that is an exact prefix match as another user-defined route, then the advertised route's next hop must be valid. If the advertised next hop is a load balancer without a configured backend pool, then this invalid route will take precedence over the user-defined route. In your network interface's effective routes, the invalid advertised route will be displayed as a user-defined route with next hop type set to **None**. 
+
 ### Why do I lose connectivity after associating a service endpoint policy to the RouteServerSubnet or GatewaySubnet?
 
 If you associate a service endpoint policy to the RouteServerSubnet or GatewaySubnet, then communication may break between Azure's underlying management platform and these respective Azure services (Route Server and VPN/ExpressRoute gateway). This can cause these Azure resources to enter an unhealthy state, resulting in connectivity loss between your on-premises and Azure workloads.
@@ -88,4 +92,4 @@ When you advertise the same routes from your on-premises network to Azure over m
 To learn how to create and configure Azure Route Server, see:
 
 > [!div class="nextstepaction"]
-> [Create and configure Azure Route Server](quickstart-configure-route-server-portal.md)
+> [Create and configure Azure Route Server](quickstart-configure-route-server-portal.md)

articles/virtual-wan/scenario-bgp-peering-hub.md

@@ -61,7 +61,7 @@ The virtual hub router now also exposes the ability to peer with it, thereby exc
 
 * When configuring BGP peering with the hub, you'll see two IP addresses. Peering with both these addresses is required. Not peering with both addresses can cause routing issues. The same routes must be advertised to both of these addresses. Advertising different routes will cause routing issues. 
 
-* The next hop IP address on the routes being advertised from the NVA to the virtual HUB route server has to be the same as the IP address of the NVA, the IP address configured on the BGP peer. Having a different IP address advertised as next hop IS NOT supported on virtual WAN at the moment.
+* The next hop IP address on the routes being advertised from the NVA to the virtual HUB route server has to be the same as the IP address of the NVA, the IP address configured on the BGP peer. Having a different IP address advertised as next hop IS NOT supported for Virtual WAN at the moment.
 ## BGP peering scenarios
 
 This section describes scenarios where BGP peering feature can be utilized to configure routing.