H3C Technologies H3C S5120 Series Switches - Manual (Page 193)

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To do... Use the command... Remarks
Configure the mode the port uses to
recognize/send MSTP packets stp compliance { auto |
dot1s | legacy }
Required
auto by default
z
MSTP provides the MSTP packet format incompatibility guard function. In MSTP mode, if a port is
configured to recognize/send MSTP packets in a mode other than auto, and receives a packet in a
format different from the specified type, the port will become a designated port and remain in the
discarding state to prevent the occurrence of a loop.
z
MSTP provides the MSTP packet format frequent change guard function. If a port receives MSTP
packets of different formats frequently, this means that the MSTP packet format configuration
contains 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 Information
In a large-scale, MSTP-enabled network, there are a large number of MSTIs, so ports may frequently
transition from one state to another. In this situation, you can enable devices to output the port state
transition 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... Remarks
Enter system view system-view —
Enable output of port state
transition information stp port-log { all | instance
instance-id }
Required
Enabled by default.
Enabling the MSTP Feature
You must enable MSTP for the device before any other MSTP-related configurations can take effect.
Make this configuration on the root bridge and on the leaf nodes separately.
Follow these steps to enable the MSTP feature:
To do... Use the command... Remarks
Enter system view system-view —
Enable the MSTP feature globally stp enable
Required
MSTP is globally disabled by
default.