Abstract: Some embodiments provide a method for a network controller operating on a host machine that hosts a particular one of multiple centralized routing components for a logical router. The method receives a routing table from a routing protocol application operating on the host machine. Each of the other centralized routing components operates on a different host machine and implements a different interface of the logical router that connects to at least one physical router external to the logical network. The routing protocol application operates as a router server for all of the centralized routing components. For each of the other centralized routing components, the method identifies a set of routes in the routing table to distribute to the centralized routing component. The method sends the identified routes for each centralized routing component to the centralized routing component.

Abstract: Some embodiments provide a method for a computing device that implements a centralized logical routing component of a logical network that handles data traffic between the logical network and an external physical network. The method receives a first routing protocol message from a machine that implements a route server for a distributed logical routing component of the logical network. The first routing protocol message includes (i) a parameter identifying the machine as a route server and (ii) a set of logical network addresses. The method receives a second routing protocol message from the route server that specifies a next hop address for the set of logical network addresses. The method adds a route specifying the next hop address for the set of logical network addresses to a routing table of the centralized logical routing component. The added route has a higher priority than routes received from the external physical network.

Abstract: Some embodiments provide a method for implementing a logical network. Based on logical network configuration data, the method identifies a route for a set of network addresses to add to a routing table of the logical router, and also identifies a route type for the identified route. The method determines whether to include the identified route as a route for the logical router to advertise based on the route type of the identified route. The method distributes a routing table comprising the identified route to a computing device that implements the logical router, where the computing device advertises the identified route when the route type is specified for advertisement.

Abstract: For a multi-tenant environment, some embodiments of the invention provide a novel method for (1) embedding a specific path for a tenant's data message flow through a network in tunnel headers encapsulating the data message flow, and then (2) using the embedded path information to direct the data message flow through the network. In some embodiments, the method selects the specific path from two or more viable such paths through the network for the data message flow.

Abstract: Some embodiments provide a method for employing the management and control system of a network to dynamically recover from a split-brain condition in the edge nodes of the network. The method of some embodiments takes a corrective action to automatically recover from a split-brain failure occurred at a pair of high availability (HA) edge nodes of the network. The HA edge nodes include an active machine and a standby machine. The active edge node actively passes through the network traffic (e.g., north-south traffic for a logical network), while the standby edge node is synchronized and ready to transition to the active state, should a failure occur. Both HA nodes share the same configuration settings and only one is active until a path, link, or system failure occurs. The active edge node also provides stateful services (e.g., stateful firewall, load balancing, etc.) to the data compute nodes of the network.

Abstract: Some embodiments provide a method for a controller that manages a physical network that implements multiple logical networks that include multiple logical routers. The method receives a command to change a particular centralized routing component of a logical router to an inactive state. At least two centralized routing components of the logical router are implemented on at least two different host machines in the physical network. The method identifies a host machine on which the particular centralized routing component operates. Other centralized routing components of other logical routers also operate on the identified host machine. The method sends a message to the identified host machine to cause the particular centralized routing component to change to an inactive state, without modifying a state of the identified host machine or the other centralized routing components operating on the identified host machine.

Abstract: Some embodiments provide a method for a controller that manages a physical network that implements multiple logical networks that include multiple logical routers. The method receives a command to change a particular centralized routing component of a logical router to an inactive state. At least two centralized routing components of the logical router are implemented on at least two different host machines in the physical network. The method identifies a host machine on which the particular centralized routing component operates. Other centralized routing components of other logical routers also operate on the identified host machine. The method sends a message to the identified host machine to cause the particular centralized routing component to change to an inactive state, without modifying a state of the identified host machine or the other centralized routing components operating on the identified host machine.

Abstract: A method for identifying a first hop router (“FHR”) in a distributed virtualized network is presented. In an embodiment, a method comprises receiving a multicast message on an incoming interface. In response to receiving the multicast message, the router determines whether the router is a FHR for the multicast message, i.e., whether, in response to generating and transmitting a hello multicast message, the router does not receive a response on the incoming interface; or whether an interface to a RP for the multicast message is different than the incoming interface. If the router is the FHR for the multicast message, then the router determines an IP address of a RP for the multicast message. The router also encapsulates the multicast message into a unicast message, includes in the unicast message the IP address of the RP as a destination address, and transmits the unicast message to the RP.

Abstract: For a network including multiple host machines that each execute a number of network functions some embodiments provide a method for the network functions to advertise the availability of the network function and network addresses (e.g., internet protocol (IP) addresses) associated with the network functions to the other network functions using application programming interfaces (APIs). In some embodiments, non-routing network functions advertise their availability and/or network addresses associated with the network function to a routing network function (e.g., a routing network function that is part of a service router) for the routing network function to advertise to other network elements (e.g. other routing elements or other network functions that need to reach the advertising network function). These advertisements, in some embodiments, are part of participation in a dynamic routing protocol.

Abstract: Example methods are provided to handle failure at one or more logical routers according to a non-preemptive mode. The method may include in response to detecting, by a first routing component operating in a standby state, a failure associated with a second routing component operating in an active state, generating a control message that includes a non-preemptive code to instruct the second routing component not to operate in the active state after a recovery from the failure, sending the control message to the second routing component, and performing a state transition from the standby state to the active state. The method may also include in response to detecting, by the first routing component operating in the active state, network traffic during the failure or after the recovery of the second routing component, forwarding the network traffic from the first network to the second network, or from the second network to the first network.

Abstract: For a set of gateway devices at the edge of a logical network, some embodiments provide a method for ensuring that data messages from an external network requiring a stateful service are received at an active gateway device. The method advertises the availability of a set of internet protocol (IP) addresses from standby gateway devices with a higher cost than the cost advertised by an active gateway device. In some embodiments, the advertisement is made using a border gateway protocol. Data messages may be unexpectedly received on a standby node despite the higher advertised cost. This could happen due to asymmetric network failures. The method determines if a stateful service is needed for the data messages received on standby node. Based on the determination, the method forwards the received data message to the active gateway device for the active gateway device to provide the stateful service.

Abstract: The technology disclosed herein enables synchronization of routing information between at least two edge systems in an edge system cluster. In a particular embodiment, a method provides, in each of the edge systems, receiving network routing information from a plurality of routers that route outbound network traffic from the edge systems and synchronizing the network routing information between the edge systems. Additionally, in each of the edge systems, the method provides receiving outbound network traffic via a logical router spanning the edge systems and routing the outbound network traffic from the edge systems in accordance with the network routing information after synchronization.

Abstract: The technology disclosed herein enables synchronization of routing information between at least two edge systems in an edge system cluster. In a particular embodiment, a method provides, in each of the edge systems, receiving network routing information from a plurality of routers that route outbound network traffic from the edge systems and synchronizing the network routing information between the edge systems. Additionally, in each of the edge systems, the method provides receiving outbound network traffic via a logical router spanning the edge systems and routing the outbound network traffic from the edge systems in accordance with the network routing information after synchronization.

Abstract: For a multi-tenant environment, some embodiments of the invention provide a novel method for (1) embedding a specific path for a tenant's data message flow through a network in tunnel headers encapsulating the data message flow, and then (2) using the embedded path information to direct the data message flow through the network. In some embodiments, the method selects the specific path from two or more viable such paths through the network for the data message flow.

Abstract: For a multi-tenant environment, some embodiments of the invention provide a novel method for (1) embedding a specific path for a tenant's data message flow through a network in tunnel headers encapsulating the data message flow, and then (2) using the embedded path information to direct the data message flow through the network. In some embodiments, the method selects the specific path from two or more viable such paths through the network for the data message flow.

Abstract: Some embodiments provide a method for employing the management and control system of a network to dynamically recover from a split-brain condition in the edge nodes of the network. The method of some embodiments takes a corrective action to automatically recover from a split-brain failure occurred at a pair of high availability (HA) edge nodes of the network. The HA edge nodes include an active machine and a standby machine. The active edge node actively passes through the network traffic (e.g., north-south traffic for a logical network), while the standby edge node is synchronized and ready to transition to the active state, should a failure occur. Both HA nodes share the same configuration settings and only one is active until a path, link, or system failure occurs. The active edge node also provides stateful services (e.g., stateful firewall, load balancing, etc.) to the data compute nodes of the network.

Abstract: Some embodiments provide a method for a network controller operating on a host machine that hosts a particular one of multiple centralized routing components for a logical router. The method receives a routing table from a routing protocol application operating on the host machine. Each of the other centralized routing components operates on a different host machine and implements a different interface of the logical router that connects to at least one physical router external to the logical network. The routing protocol application operates as a router server for all of the centralized routing components. For each of the other centralized routing components, the method identifies a set of routes in the routing table to distribute to the centralized routing component. The method sends the identified routes for each centralized routing component to the centralized routing component.

Abstract: For a network including multiple host machines that each execute a number of network functions some embodiments provide a method for the network functions to advertise the availability of the network function and network addresses (e.g., internet protocol (IP) addresses) associated with the network functions to the other network functions using application programming interfaces (APIs). In some embodiments, non-routing network functions advertise their availability and/or network addresses associated with the network function to a routing network function (e.g., a routing network function that is part of a service router) for the routing network function to advertise to other network elements (e.g. other routing elements or other network functions that need to reach the advertising network function). These advertisements, in some embodiments, are part of participation in a dynamic routing protocol.

Abstract: Some embodiments provide a method for employing the management and control system of a network to dynamically recover from a split-brain condition in the edge nodes of the network. The method of some embodiments takes a corrective action to automatically recover from a split-brain failure occurred at a pair of high availability (HA) edge nodes of the network. The HA edge nodes include an active machine and a standby machine. The active edge node actively passes through the network traffic (e.g., north-south traffic for a logical network), while the standby edge node is synchronized and ready to transition to the active state, should a failure occur. Both HA nodes share the same configuration settings and only one is active until a path, link, or system failure occurs. The active edge node also provides stateful services (e.g., stateful firewall, load balancing, etc.) to the data compute nodes of the network.

Abstract: Some embodiments provide method for implementing a logical router of a logical network. The method receives a configuration for a first logical router. The configuration includes a static route for the first logical router. The method defines several routing components with separate routing tables for the logical router. The method adds a first route, having a first static route type, for the static route to the routing tables of at least a first subset of the routing components. Based on the connection of a second logical router to the first logical router, adding a second route, having a second static route type, to the routing tables of at least a second subset of the routing components.