Dynamic service chain provisioning

A network device comprising:

• at least one memory;
• and
• processing circuitry operably coupled to the at least one memory, wherein the processing circuitry is configured to:
• receive configuration data defining a plurality of virtual private network (VPN) routing and forwarding tables (VRFs);
• receive a first ordered list of VRFs from the plurality of VRFs, wherein each VRF in the first ordered list of VRFs represents a start point of a corresponding service from a plurality of services including a first service and a second service;
• receive a second ordered list of VRFs from the plurality of VRFs, wherein each VRF in the second ordered list of VRFs represents an end point of a corresponding service from the plurality of services;
• receive a packet of a packet flow from a first service node that has applied the first service to the packet;
• and
• send, based at least on the ordered list of services, the packet to a second service node that applies the second service.

A non-transitory computer-readable storage medium comprising instructions for causing one or more programmable processors to:

• configure, by a gateway coupled to a plurality of service nodes by respective virtual private networks (VPNs), a separate input virtual routing and forwarding table (VRF) and output VRF for each of the VPNs;
• receive, by the gateway, an ordered list specifying a service chain for processing packets of a packet flow through an ordered set of the service nodes, wherein the ordered list specifies the service chain as a first ordered list of input VRFs from the plurality of the input VRFs and as a second ordered list of output VRFs from the plurality of output VRFs,
• wherein each input VRF in the first ordered list of input VRFs represents a start point of a corresponding service,
• wherein each output VRF in the second ordered list of output VRFs represents an end point of a corresponding service, and
• wherein the first ordered list and the second ordered list define a sequence of the VPNs associated with the service nodes;
• and
• send and receive, by the gateway, packets of the packet flow in accordance with the first ordered list and the second ordered list to forward packets along the service chain.

A system comprising:

• a first service node configured to apply a first service;
• a second service node configured to apply a second service;
• and
• a network device comprising at least one processor coupled to a memory,
• wherein the network device is configured to receive a first ordered list of virtual private network (VPN) routing and forwarding tables (VRFs) from the plurality of VRFs, wherein each VRF in the first ordered list of VRFs represents a start point of a corresponding service from a plurality of services including a first service and a second service;
• wherein the network device is configured to receive a second ordered list of VRFs from the plurality of VRFs, wherein each VRF in the second ordered list of VRFs represents an end point of a corresponding service from the plurality of services,
• wherein the network device is configured to receive a packet of a packet flow from the first service node that has applied the first service to the packet,
• wherein the network device is configured to send, based at least on the first ordered list and the second ordered list the packet to the second service node configured to apply the second service.