Overview of LBDT

LBDT periodically sends detection packets through an interface to detect loops on the interface, on the downstream network or device, or between two device interfaces.

When a loop occurs on a network, broadcast, multicast, and unknown unicast packets are circulated on the network. This wastes network resources and can result in network breakdowns. Quickly detecting loops on a Layer 2 network is crucial for users to minimize the impact of loops on a network. LBDT helps users check network connections and configurations, and control the looped interface.

LBDT periodically sends detection packets on an interface to check whether the packets return to the local device (through the same interface or another interface), and determines whether a loop occurs on the interface, on the downstream network or device, or between two device interfaces. After a loop is detected, the device sends a trap to the NMS and records a log, and takes a preconfigured action on the looped interface (the interface is shut down by default) to minimize impact of the loop on the device and entire network.

LBDT can only detect loops on a single node, but cannot eliminate loops in the same manner as ring network technologies including ERPS, RRPP, SEP, Smart Link, STP, RSTP, MSTP, and VBST.