4-28z dot1s: 802.1s-compliant standard format, andz legacy: Compatible formatBy default, the packet format recognition mode of a port is auto, namely the port automaticallydistinguishes the two MSTP packet formats, and determines the format of packets it will send based onthe recognized format. You can configure the MSTP packet format on a port. After the configuration,when working in MSTP mode, the port sends and receives only MSTP packets of the format you haveconfigured to communicate with devices that send packets of the same format.Make this configuration on the root bridge and on the leaf nodes separately.Follow these steps to configure the MSTP packet format to be supported on a port or a group of ports:To do... Use the command... RemarksEnter system view system-view —Enter Ethernetinterface view, orLayer 2aggregateinterface viewinterface interface-typeinterface-numberEnterinterfaceview orport groupview Enter port groupviewport-group manualport-group-nameRequiredUse either command.Configure the mode the portuses to recognize/send MSTPpacketsstp compliance { auto | dot1s |legacy }Requiredauto by defaultz MSTP provides the MSTP packet format incompatibility guard function. In MSTP mode, if a port isconfigured to recognize/send MSTP packets in a mode other than auto, and receives a packet ina format different from the specified type, the port will become a designated port and remain in thediscarding state to prevent the occurrence of a loop.z MSTP provides the MSTP packet format frequent change guard function. If a port receives MSTPpackets of different formats frequently, this means that the MSTP packet format configurationcontains errors. In this case, if the port is working in MSTP mode, it will be disabled for protection.Those ports closed thereby can be restored only by the network administrators.Enabling the Output of Port State Transition InformationIn a large-scale, MSTP-enabled network, there are a large number of MSTIs, so ports may frequentlytransition from one state to another. In this situation, you can enable devices to output the port statetransition information of all MSTIs or the specified MSTI so as to monitor the port states in real time.Make this configuration on the root bridge and on the leaf nodes separately.Follow these steps to enable output of port state transition information:To do... Use the command... RemarksEnter system view system-view —
