Dell N3200-ON Networking N-Series Switches User Guide version 6.8.0 - Page 1681

Collect Port and Queue Status and Statistics The OpenFlow Controller can collect status and statistics for ports and queues. When ports are created, Dell Networking OpenFlow Hybrid sends an OFPT_PORT_STATUS message to the OpenFlow Controller. The status message is triggered by creation of entries in the Physical Port Table. The same tables are used for reporting port status information. The port status is updated by a separate task that periodically polls the status for all physical ports. To avoid performance issues, the statistics are polled every 10 seconds for a maximum of 100 interfaces. For physical ports, the switch also reads the queue statistics for all eight queues at the same time as it reads the port statistics. The LAG statistics are reported as a sum of statistics for all active LAG member ports. This implies that when a port is removed from the LAG, the statistics counters for the LAG go down. Also, when all ports are removed from a LAG, the LAG statistics are reported as 0. Usage Scenarios The OpenFlow feature is mainly targeted for deployment in a data center network where devices located in different parts of the network require Layer2 connectivity. The OpenFlow feature enables customers to avoid scaling problems and loops associated with the Layer-2 network. The OpenFlow feature can also be used in a research environment, but there are two limitations that may make the "research" use case less attractive. First, there is only one OpenFlow instance, meaning that concurrent experiments are not supported at the switch level. Second, the OpenFlow controller has complete access to all ports and VLANs; therefore, using the switch for mixed production and experimental traffic is not advisable. Eligible Interfaces The OpenFlow application affects traffic forwarding on physical ports and LAGs. OpenFlow 1681