A network switch includes a receive port configured to receive data and two or more parallel first paths each configured to receive a first copy of the data, perform a check on the first copy, and generate a protection for the first copy. One or more first voter elements are configured to receive second copies of the data and to crosscheck the second copies. A processing section is configured to process one or more of the second copies. Two or more parallel second paths are each configured to receive a third copy of the data and perform multiple checks on the third copy including a check based on the protection. One or more second voter elements are configured to receive fourth copies of the data and to crosscheck the fourth copies. A send port is configured to send one or more of the fourth copies to a next network element.

The present disclosure pertains to improving resilience to single event upsets (“SEUs”) in a software-defined network (“SDN”). In one embodiment, a system may include a communications interface to receive and transmit a data packet. A primary data flow repository may store a plurality of communication flows to be used to route the data packet. A secondary data flow repository may store a subset of communication flows to be used to route a data packet. A system may search the plurality of communication flows in the primary data flow repository based on a criteria associated with the data packet. If no communication flow satisfies the criteria, a secondary data flow repository may be searched. The data packet may be routed according to a communication flow in the secondary data flow repository. The communication flow from the secondary data flow repository may be duplicated in the primary data flow repository.

Techniques are described for managing a split-brain scenario in a multihomed environment by exchanging isolation information between a leaf device and two or more spine devices to which the leaf device is multihomed via a link aggregation group (LAG). The techniques include selecting one of the spine devices as a primary spine device and determining, based on the isolation information, whether the spine devices are isolated from each other. In the split-brain scenario in which all of the spine devices are isolated from each other, the primary spine device is configured to maintain the LAG with the leaf device while the other spine devices mark the LAG with the leaf device as down. In this way, in the split-brain scenario, the leaf device may continue to send traffic to other leaf devices in the leaf layer using the LAG to the primary spine device.

A system, method, and apparatus may provide one or more tangible, nontransitory computer-readable storage media having stored thereon executable instructions to instruct a processor to: stripe an outgoing network message into two or more pieces; send a first piece to a receiver via a first network interface card (NIC), and a second piece to the receiver via a second NIC; and upon determining that the receiver failed to receive a piece of the outgoing network message, replay the piece that the receiver failed to receive via a third NIC.

A non-transitory computer-readable recording medium stores a program for causing a computer that operates as an operation node in an information processing system which includes the operation node, a standby node corresponding to the operation node, and a network node which relays communication from a client node to the operation node or the standby node, to execute a process including: acquiring first information that is an output of a serverless function executed by the information processing system and indicates a result of coupling checking by the serverless function for a first service used for monitoring of the network node by the operation node; and controlling whether or not to switch a node of an access destination by the client node via the network node from the operation node to the standby node, based on the first information.

Some embodiments provide a method for quantifying quality of several service classes provided by a link between first and second forwarding nodes in a wide area network (WAN). At a first forwarding node, the method computes and stores first and second path quality metric (PQM) values based on packets sent from the second forwarding node for the first and second service classes. The different service classes in some embodiments are associated with different quality of service (QoS) guarantees that the WAN offers to the packets. In some embodiments, the computed PQM value for each service class quantifies the QoS provided to packets processed through the service class. In some embodiments, the first forwarding node adjusts the first and second PQM values as it processes more packets associated with the first and second service classes. The first forwarding node also periodically forwards to the second forwarding node the first and second PQM values that it maintains for the first and second service classes. In some embodiments, the second forwarding node performs a similar set of operations to compute first and second PQM values for packets sent from the first forwarding node for the first and second service classes, and to provide these PQM values to the first forwarding node periodically.

An example operation may include a system, comprising one or more of receiving a VNFCI status notification resumption with an active state, retrieving a timestamp of the VNFCI state change to active, retrieving a timestamp of a peer VNFCI state change to active, checking with a VIM to determine if the VNFCI network isolated while active, checking with the VIM to determine if the peer VNFCI network isolated while active, sending a first state change request message with standby to the peer VNFCI when one or more of: the peer VNFCI was network isolated, and the VNFCI was not network isolated, sending a second state change request message with standby to the peer VNFCI when one or more of: the VNFCI is not the preferred standby instance, and the peer VNFCI was not network isolated, and the VNFCI was not network isolated, starting a first retry timer for the peer VNFCI when one or more of: the first state change request message is sent, and the second state change request message is sent, sending a third state change request message with standby to the VNFCI when one or more of: the VNFCI is the preferred standby instance, and the peer VNFCI was network isolated, and the VNFCI was network isolated, sending a fourth state change request message with standby to the VNFCI when one or more of: the peer VNFCI was not network isolated, and the VNFCI was network isolated, and starting a second retry timer for the VNFCI when one or more of: the third state change request message is sent, and the fourth state change request message is sent.

A communication device redundantly configured with another communication device includes: a first port configured to transmit a packet through a second communication line configuring link aggregation with a first communication line of the other communication device; a second port configured to transmit and receive a packet through a fourth communication line configuring link aggregation with a third communication line of the other communication device; a third port configured to transmit a packet to the other communication device through a fifth communication line; and a first processor configured to: transfer a packet received by the second port to the first port or the third port; detect a failure of the second communication line; detect a failure of the fifth communication line; and shut down the second port when detecting the failure of the second communication line and the failure of the fifth communication line.

A method of identifying a failed egress path of a hardware forwarding element. The method detects an egress link failure in a data plane of the forwarding element. The method generates a link failure signal in the data plane identifying the failed egress link. The method generates a packet that includes the identification of the egress link based on the link failure signal. The method sets the status of the egress link to failed in the data plane based on the identification of the egress link in the generated packet.

Systems and methods are provided for collecting data related to changes to a data store table, which may be used for analyzing problems that occur in the network. The information monitored may include types of changes made to a data store/table, such as insertions and deletions of data store elements. When an anomaly occurs in the statistical data store/table data, an alert is issued. This statistical data of the types of changes to a data store may be suggestive of similar changes in a network. For example, the uptime, inactive time, and stable time of rows of a data store table may be used for estimating or inferring the uptime, inactive time, and stable time for nodes, data paths, or other elements of a network. The system may include a web UI or a command line interface, which may aid in diagnosing problems in the network, and taking corrective action.