Some embodiments provide stateful services in a chain of services identified for some data messages. The edge forwarding element receives a data message at a particular interface of the edge forwarding element that is traversing the edge forwarding element in a forward direction between two machines. The edge forwarding element identifies (1) a set of stateful services for the received data message and (2) a next hop associated with the identified set of stateful services in the forward direction and a next hop associated with the identified set of stateful services in the reverse direction. Based on the identified set of services and the next hops for the forward and reverse directions, the edge forwarding element generates and stores first and second connection tracking records for the forward and reverse data message flows, respectively used to forward data messages received subsequently for the flow.

Some embodiments provide novel methods for providing different types of services for a logical network associated with an edge forwarding element acting between the logical network and an external network. The edge forwarding element receives data messages for forwarding and performs a service classification operation to select a set of services of a particular type for the data message. The particular type of service is one of multiple different types of services that use different transport mechanisms to forward the data to a set of service nodes (e.g., service virtual machines, or service appliances, etc.) that provide the service. The edge forwarding element then receives the data message after the selected set of services has been performed and performs a forwarding operation to forward the data message. In some embodiments, the method is also performed by edge forwarding elements that are at the edges of logical network segments within the logical network.

Some embodiments facilitate the provision of a service reachable at a virtual internet protocol (VIP) address. The VIP address is used by clients to access a set of service nodes in the logical network. Facilitating the provision of the service, in some embodiments, includes returning a serviced data message to a load balancer that selected a service node to provide the service for the load balancer to track the state of the connection using the service logical forwarding element. To use the service logical forwarding element, some embodiments configure an egress datapath of the service nodes to intercept the serviced data message before being forwarded to a logical forwarding element in the datapath from the client to the service node, and determine if the serviced data message requires routing by the routing service provided as a service by the edge forwarding element.

For traffic exiting a logical network through a particular VTI, some embodiments perform a service classification operation for different data messages to identify different VTIs that connect the edge forwarding element to a service node to provide services required by the data messages. Each data message, in some embodiments, is then forwarded to the identified VTI to receive the required service. The identified VTI does not perform a service classification operation. The service node then returns the serviced data message to the edge forwarding element. In some embodiments, the identified VTI is not configured to perform the service classification operation and is instead configured to mark all traffic directed to the edge forwarding element as having been serviced. The marked serviced data message is received at the edge forwarding element and forwarded to a destination of the data message through the particular VTI.

Some embodiments provide novel methods for providing a set of services for a logical network associated with an edge forwarding element acting between a logical network and an external network. In some embodiments, the services are provided using a logical service forwarding plane that connects the edge forwarding element to a set of service nodes that each provide a service in the set of services. The service classification operation of some embodiments identifies a chain of multiple service operations that has to be performed on the data message. In some embodiments, identifying the chain of service operations includes selecting a service path to provide the multiple services. After selecting the service path, the data message is sent along the selected service path to have the services provided. The data message is returned to the edge forwarding element by a last service node in the service path that performs the last service operation and the edge forwarding element performs next hop forwarding on the data message.

Techniques are disclosed for identifying faulty links in a virtualized computing environment. Network path latency information is received for one or more network paths in the networked computing environment. Based on the network path latency information, a probable presence of a faulty component is determined. In response to the determination, physical links for a network path associated with the probable faulty component are identified. Information indicative of likely sources of the probable faulty component is received from multiple hosts of the networked computing environment. Based on the identified physical links and information, a faulty component is determined.

Techniques are disclosed for identifying faulty links in a virtualized computing environment. Network path latency information is received for one or more network paths in the networked computing environment. Based on the network path latency information, a probable presence of a faulty component is determined. In response to the determination, physical links for a network path associated with the probable faulty component are identified. Information indicative of likely sources of the probable faulty component is received from multiple hosts of the networked computing environment. Based on the identified physical links and information, a faulty component is determined.

Techniques for routing data packets through service chains within and between public cloud networks of multi-cloud fabrics. A router in a network, e.g., a public cloud network, receives data packets from nodes in the network through segments of the network. Based at least in part on (i) a source address of the data packet, (ii) a destination address of the data packet, and (iii) an identity of the segments of the network from which the data packets are received, the router determines a next node in the network to which the data packet is to be forwarded. The router may then forward the data packet through another segment of the network to the next node and then receive the data packet from the next node through the another segment.

A network device receives a data packet including a source address and a destination address. The network device drops the data packet before it reaches the destination address and generates an error message indicating that the data packet has been dropped. The network device encapsulates the error message with a segment routing header comprising a list of segments. The first segment of the list of segments in the segment routing header identifies a remote server, and at least one additional segment is an instruction for handling the error message. The network device sends the encapsulated error message to the remote server based on the first segment of the segment routing header.

In general, the disclosure describes techniques for measuring edge-based quality of experience (QoE) metrics. For instance, a network device may construct a topological representation of a network, including indications of nodes and links connecting the nodes within the network. For each of the links, the network device may select a node device of the two node devices connected by the respective link to measure one or more QoE metrics for the respective link, with the non-selected node device not measuring the QoE metrics. In response to selecting the selected node device, the network device may receive a set of one or more QoE metrics for the respective link for data flows flowing from the selected node device to the non-selected node device. The network device may store the QoE metrics and determine counter QoE metrics for data flows flowing from the non-selected node device to the selected node device.