Abstract: A method is performed by a network device acting as a controller in a software defined networking (SDN) network. The method detects control path loops in the SDN network. The method includes receiving a Packet-In message from a switch, where the Packet-In message includes a packet. The method further includes determining a packet identifier associated with the packet, determining a key based on the packet identifier associated with the packet, determining whether an entry associated with the key exists in a loop detection cache, updating a counter value associated with the entry in response to determining that the entry associated with the key exists in the loop detection cache, and determining that the packet is in a control path loop in response to determining that the counter value associated with the entry reaches a threshold value.

Abstract: Temporal matching based debugging methods are disclosed. In one embodiment, the method is implemented in a software-defined networking (SDN) controller coupled to a SDN system. The SDN system contains a set of network devices managed by the SDN controller, the method includes recording, at the SDN controller, messages between the SDN controller and a network device. The method further includes obtaining at the SDN controller from the network device, a set of statistics from the network device, where the set of statistics indicates characteristics of packet processing at the network device. The method further includes temporally matching the set of statistics obtained from the network device with the messages recorded, and identifying, among the messages recorded at the SDN controller, one or more messages occurred when the set of statistics indicates a packet processing anomaly in the network device.

Abstract: A method is performed by a network device acting as a controller in a software defined networking (SDN) network. The method detects control path loops in the SDN network. The method includes receiving a Packet-In message from a switch, where the Packet-In message includes a packet. The method further includes determining a packet identifier associated with the packet, determining a key based on the packet identifier associated with the packet, determining whether an entry associated with the key exists in a loop detection cache, updating a counter value associated with the entry in response to determining that the entry associated with the key exists in the loop detection cache, and determining that the packet is in a control path loop in response to determining that the counter value associated with the entry reaches a threshold value.

Abstract: Temporal matching based debugging methods are disclosed. In one embodiment, the method is implemented in a software-defined networking (SDN) controller coupled to a SDN system. The SDN system contains a set of network devices managed by the SDN controller, the method includes recording, at the SDN controller, messages between the SDN controller and a network device. The method further includes obtaining at the SDN controller from the network device, a set of statistics from the network device, where the set of statistics indicates characteristics of packet processing at the network device. The method further includes temporally matching the set of statistics obtained from the network device with the messages recorded, and identifying, among the messages recorded at the SDN controller, one or more messages occurred when the set of statistics indicates a packet processing anomaly in the network device.