Abstract: Some embodiments provide a novel network control system that provides publications for managing different slices (e.g., logical and/or physical entities) of a network. The publications are published from publisher controllers in the network control system to subscriber controllers. The network control system uses publications with generation numbers and buffered subscribers to implement the fixed points in order to help maintain a consistent network state. The information published with a publication is useful for resolving conflicts in the network control system when multiple publisher controllers provide conflicting inputs to a subscriber controller.

Abstract: Some embodiments provide a method for a network controller. The method receives configuration data, for a logical router managed by the network controller, that specifies at least one logical port for the logical router. The method automatically generates connected routes for the logical router based on network address ranges specified for the logical ports of the logical router. The method receives a manually input static route for the logical router. The method generates data tuples, for distribution to several managed network elements, based on the connected and static routes for the logical router in order for the several managed network elements to implement the logical router.

Abstract: Some embodiments provide a network controller for managing a logical network implemented across several managed network elements. The logical network includes at least one logical router. The network controller includes an input interface for receiving configuration state for the logical router. The network controller includes a table mapping engine for generating data tuples for distribution to the managed network elements in order for the managed network elements to implement the logical router. The network controller includes a route processing engine for receiving a set of input routes from the table mapping engine based on the configuration state for the logical router, performing a recursive route traversal process to generate a set of output routes, and returning the set of output routes to the table mapping engine. The table mapping engine uses the set of output routes to generate the data tuples for distribution to the plurality of managed network elements.

Abstract: Some embodiments provide a method for an application operating on a host machine. The method receives a configuration of a Dynamic Host Configuration Protocol (DHCP) service for implementation within a virtualized container on the host machine. The configuration includes several database table entries. The method converts the several database table entries into a configuration file for use by a process that operates in the virtualized container. the method initializes the process in the virtualized container. The process in the virtualized container reads the configuration file in order to perform DHCP services for machines connected to at least one logical forwarding element of a logical network.

Abstract: Some embodiments provide a method for a network controller that manages several logical networks. The method receives a specification of a logical network that includes at least one logical forwarding element attached to a logical service (e.g., DHCP). The method selects at least one host machine to host the specified logical service from several host machines designated for hosting logical services. The method generates logical service configuration information for distribution to the selected host machine. In some embodiments, the method selects a master host machine and a backup host machine for hosting logical service. In some embodiments, a particular one of the designated host machines hosts at least two DHCP services for two different logical networks as separate processes operating on the particular host machine.

Abstract: Some embodiments provide a method for a network controller that manages several managed forwarding elements. The method receives a request to trace a specified packet having a particular source on a logical switching element. The method generates the packet at the network controller according to the packet specification. The generated packet includes an indicator that the packet is for a trace operation. The method inserts the packet into a managed forwarding element associated with the particular source. The method receives a set of messages from a set of managed forwarding elements that process the packet regarding operations performed on the packet.

Abstract: Some embodiments provide a method for a network controller that manages a plurality of managed forwarding elements. The method receives a request to trace a specified packet having a particular source on a logical forwarding element. The method generates the packet according to the packet specification. The generated packet includes an indicator that the packet is for a trace operation. The method inserts the packet into a managed forwarding element associated with the particular source such that the managed forwarding element processes the packet as though the packet was received from the particular source. The method receives, from a set of managed forwarding elements, a set of messages regarding logical processing operations and physical forwarding operations that each managed forwarding element in the set of managed forwarding elements performs on the packet.

Abstract: Some embodiments provide a method for a managed forwarding element that operates on a host machine to process packets for at least one logical network. The method receives a packet that includes a particular piece of data to maintain with the packet. The particular piece of data is not stored in a payload of the packet and is not protocol-specific data. The method stores the particular piece of data in a register while processing the packet. The method identifies a next destination of the packet that operates on the host machine. The method generates an object to represent the packet for the identified destination. The particular piece of data is stored in a field of the generated object.

Abstract: Some embodiments provide a method for a first network controller that manages a set of logical forwarding elements implemented in several managed forwarding elements. The method receives a request to trace a specified packet having a particular source on a logical forwarding element. The method generates the packet according to the packet specification. The generated packet includes an indicator that the packet is for a trace operation. The method sends the packet to a second network controller that manages a managed forwarding element associated with the particular source. The method receives a first set of messages regarding operations performed on the packet from a set of network controllers that receives a second set of messages regarding operations performed on the packet from a set of managed forwarding elements that process the packet.

Abstract: A network control system that achieves high availability for forwarding state computation within a controller cluster by replicating different levels of table state between controllers of the controller cluster. To build a highly available controller cluster, the tables for storing the forwarding state are replicated across the controllers. In order to reduce network traffic between the controllers, fewer tables are replicated to slave controllers, which then recompute the forwarding state of the master controller in order to have a replicate copy of the master controller's forwarding state for possible failover. In other embodiments, more tables are replicated to minimize the recomputations and processor load on the slave controller. The network control system of some embodiments performs continuous snapshotting to minimize downtime associated with reaching a fixed point and replicating the state.

Abstract: A network control system that achieves high availability for forwarding state computation within a controller cluster by replicating different levels of table state between controllers of the controller cluster. To build a highly available controller cluster, the tables for storing the forwarding state are replicated across the controllers. In order to take responsibility for a slice, the slave controller of some embodiments performs merging of replicated state on a slice-by-slice basis. The merging is performed in a manner to prevent disruptions to the network state while the slave controller is updated.