US Patent 9692696 Managing data flows in overlay networks

Embodiments relate to managing data flows at a virtual forwarding element. A method for managing data flows at a virtual forwarding element executing in a host that has a network interface card (NIC) is provided. The method receives, from a virtual machine executing in the host, a packet that belongs to a data flow originating from the virtual machine. The method identifies a network identifier for the data flow based on a mapping between a plurality of virtual machines executing in the host and a plurality of network identifiers. The mapping is provided by a network controller that configures the virtual forwarding element. The method encapsulates the packet with the network identifier and a tunnel header that includes network addresses of the host. The method sends the encapsulated packet to the NIC. The NIC transmits the encapsulated packet out of the host and towards a destination of the packet.