1-40We recommend that you keep this feature enabled.Enabling BPDU DroppingIn a STP-enabled network, some users may send BPDU packets to the switch continuously in order todestroy the network. When a switch receives the BPDU packets, it will forward them to other switches.As a result, STP calculation is performed repeatedly, which may occupy too much CPU of the switchesor cause errors in the protocol state of the BPDU packets.In order to avoid this problem, you can enable BPDU dropping on Ethernet ports. Once the function isenabled on a port, the port will not receive or forward any BPDU packets. In this way, the switch isprotected against the BPDU packet attacks so that the STP calculation is assured to be right.Follow these steps to enable BPDU dropping:To do... Use the command... RemarksEnter system view system-view —Enter Ethernetinterface viewor Layer-2aggregateinterface viewinterface interface-typeinterface-numberEnterinterface viewor port groupviewEnter portgroup viewport-group manualport-group-nameRequiredUse either command.Configurations made ininterface view will take effecton the current port only;configurations made in portgroup view will take effect onall ports in the port group.Enable BPDU dropping for theport(s) bpdu-drop any RequiredDisabled by defaultDisplaying and Maintaining MSTPTo do... Use the command... RemarksView information aboutabnormally blocked ports display stp abnormal-port Available in any viewView information about portsblocked by STP protectionfunctionsdisplay stp down-port Available in any viewView the information of port rolecalculation history for thespecified MSTI or all MSTIsdisplay stp [ instanceinstance-id ] history [ slotslot-number ]Available in any viewView the statistics of TC/TCNBPDUs sent and received by allports in the specified MSTI orall MSTIsdisplay stp [ instanceinstance-id ] tc [ slotslot-number ]Available in any view
