Patent ID: 11870677
Assignee: JUNIPER NETWORKS, INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method comprising:
storing, by a Software Defined Networking (SDN) controller, an underlay routing table having a set of underlay network routes for an underlay network of a data center, wherein the underlay network includes a plurality of physical network switches that form an Internet Protocol (IP) fabric and a set of virtual routers executing on respective compute nodes of the data center;
storing, by the SDN controller, an overlay routing table having a set of virtual private network (VPN) routes for at least one virtual network of an overlay network for the data center, the at least one virtual network provided by one of the set of virtual routers;
receiving, by the SDN controller and from one of the plurality of physical network switches of the IP fabric that peers with the SDN controller by a routing protocol session, an underlay network route to a destination address assigned to a particular one of the virtual routers;
installing, by the SDN controller and within the underlay routing table of the SDN controller, the received underlay network route as an indicator of a reachability status in the underlay network from another one of the plurality of physical network switches to the particular one of the virtual routers;
prior to advertising a VPN route for the at least one virtual network, performing a next hop reachability check to determine whether a corresponding underlay network route for the VPN route exists in the underlay routing table; and
controlling, by the SDN controller and based on a presence or absence of the underlay network route within the underlay routing table to the particular one of the virtual routers, advertisement of one or more of the VPN routes for the at least one virtual network of the overlay network.