Loop and pause flood protection
Loop protection The loop protection feature enables detection of loops on downlink ports, which can be Flex-10 logical ports or physical ports. The feature applies when Device Control Channel (DCC) protocol is running on the Flex-10 port. If DCC is not available, the feature applies to the physical downlink port. Network loop protection uses two methods to detect loops: It periodically injects a special probe frame into the HP Virtual Connect domain and monitors downlink ports for the looped back probe frame. If this special probe frame is detected on downlink ports, the port is considered to cause the loop condition. It monitors and intercepts common loop detection frames used in other switches. In network environments where the upstream switches send loop detection frames, the HP Virtual Connect interconnects must ensure that any downlink loops do not cause these frames to be sent back to the uplink ports. Even though the probe frames ensure loops are detected, there is a small time window depending on the probe frame transmission interval in which the loop detection frames from the external switch might loop through down link ports and reach uplink ports. By intercepting the external loop detection frames on downlinks, the...
