US Patent 9319375 Flow templating in logical L3 routing

For a network controller for managing hosts in a network, a method for configuring a host to handle flow entries and template flow entries is described. The method generates a template flow entry to be populated in order to create a flow entry for a particular managed forwarding element. The method sends the template flow entry to the particular forwarding element in a host. The method configures a flow entry generating flow entry generating module in a host to create the flow entry by populating the template flow entry. The method configures the particular managed forwarding element to (1) send the template flow entry to the flow entry generating flow entry generating module (2) forward packets using the flow entry created by the flow entry generating flow entry generating module.