Auto discovery and auto scaling of services in software-defined network environment

A method comprising:

• establishing, by a gateway network device, a border gateway protocol (BGP) peer session with a software-defined networking (SDN) controller;
• receiving, by the gateway network device and from the SDN controller via the BGP peer session, advertisements of BGP routes for a given service as load balancing entities, wherein each of the BGP routes represents one of a set of two or more unique tunnels that each extends from the gateway network device to a respective one of a set of two or more virtual service instances configured to apply the given service to a packet;
• maintaining, by the gateway network device, a load balancing group for the given service that includes each of the BGP routes for the given service;
• and
• selecting, by the gateway network device and according to a load balancing algorithm, one of the BGP routes from the load balancing group on which to forward the packet to the respective one of the virtual service instances for application of the given service.

A gateway network device comprising:

• a plurality of network interfaces;
• a control unit comprising a processor executing a boarder gateway protocol (BGP) to establish a BGP peer session on one of the network interfaces with a software-defined networking (SDN) controller, the processor configured to receive advertisements of BGP routes for a given service as load balancing entities on the one of the network interfaces via the BGP peer session with the SDN controller, wherein each of the BGP routes represents one of a set of two or more unique tunnels that each extends from the gateway network device to a respective one of a set of two or more virtual service instances configured to apply the given service to a packet, and maintain a load balancing group for the given service that includes each of the BGP routes for the given service;
• and
• a forwarding circuit programmed with forwarding information associated with the BGP routes, the forwarding circuit configured to select one of the BGP routes for the packet from the load balancing group according to a load balancing algorithm, wherein the forwarding circuit outputs the packet to one of the network interfaces for forwarding to the respective one of the virtual service instances for application of the given service.