MSTP Configuration Commands 189interface-number ] }&<1-10>. For detail descriptions of interface-type andinterface-number parameters, refer to the corresponding descriptions in PortCommand Manual. &<1-10> means that the preceding parameters can beentered up to 10 timesDescriptionUse the stp interface loop-protection command to enable loop protection onthe switch in system view.Use the undo stp interface loop-protection command to restore the defaultloop protection state.When port roles change, you can use the stp interface loop-protectioncommand to change port state from forwarding state to discarding state, thusavoiding port loopback.Use the undo stp interface loop-protection command to restore the defaultrunning state of loop protection in system view.The root port and other blocked ports maintain their state according to the BPDUssent by uplink switch. Due to link congestion or unidirectional link failure, theseports may be unable to receive BPDUs and the switch will select root port again. Inthis case, the former root port will turn into the specified port and the formerblocked ports will change to the forwarding state, and link loop appears.The loop protection function can inhibit the generation of loop. After it is enabled,the root port role will change according to the uplink port state. The blocked portwill maintain in discarding state and do not forward packets, thus avoiding linkloop.By default, loop protection is disabled.c CAUTION: If the equipment connected to the port of the switch cannot send STPpackets to the switch, do not configure the loop-protection command;otherwise the port will be congested for a long time.Related command: stp loop-protection.n For a loopback port, if the port participates in STP calculation, it must be specifiedport regardless of internal loop or external loop. However, the port is always set tobe in discarding state on all instances.Example# Enable loop protection on the Ethernet2/1/1.system-viewSystem View: return to User View with Ctrl+Z.[SW8800] stp interface Ethernet2/1/1 loop-protectionstp interface mcheck Syntaxstp interface interface-list mcheckViewSystem view
