Inter-network service chaining

A method comprising:

• obtaining, by a controller and from a switch in a destination network, an Ethernet Virtual Private Network (EVPN) route that specifies a next hop to an Internet Protocol (IP) address of a bare metal server reachable by the destination network;
• generating, by the controller, a first modified IP route that specifies a service node as a next hop for the destination address;
• generating, by the controller, a second modified IP route that specifies the switch as the next hop for the destination address, wherein the switch is directly connected to the bare metal server;
• sending, by the controller, the first modified IP route to a router of a source network to configure the router of the source network to send traffic originating from the virtual machine and destined for the bare metal server to the service node;
• and
• sending, by the controller, the second modified IP route to a router of the destination network to configure the router of the destination network to send the traffic received from the service node to the switch.

A controller comprising:

• one or more processors;
• a control unit executed by the one or more processors configured to obtain a route from a destination network that specifies a next hop to a destination address reachable by the destination network;
• and
• a service chain unit executed by the one or more processors configured to:
• generate a first modified route that specifies a service node as the next hop for the destination address, wherein the service node is external to the destination network;
• generate a second modified route that specifies a server hosting the service node as the next hop for the destination address;
• send the second modified route to a switch of a source network to configure the switch to send traffic from a bare metal server to the server hosting the service node, wherein the traffic is originated from the bare metal server and destined for the source network;
• and
• send the first modified route to a router of the source network to configure the router of the source network to send the traffic received from the switch to the service node.