Explanation
References:
https://docs.microsoft.com/en-us/windows-server/remote/remote-access/bgp/border-gateway-protocol-bgp
https://docs.microsoft.com/en-us/windows-server/remote/remote-access/bgp/border-gateway-protocol-bgp When configured on a Windows Server 2016 Remote Access Service (RAS) Gateway in multitenant mode, Border Gateway Protocol (BGP) provides you with theability to manage the routing of network traffic between your tenants' VM networks and their remote sites. You can also use BGP for single tenant RAS Gatewaydeployments, and when you deploy Remote Access as a Local Area Network (LAN) router.BGP reduces the need for manual route configuration on routers because it is a dynamic routing protocol, and automatically learns routes between sites that areconnected by using site-to-site VPN connections.To use BGP routing, you must install the Remote Access Service (RAS) and/or the Routing role service of the Remote Access server role on a computer or virtualmachine (VM) - the type of system you use depends on whether or not you have a multitenant deployment.