H3C Technologies H3C S7500E Series Switches - Manual (Page 193)

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Among loop guard, root guard and edge port settings, only one function (whichever is configured the
earliest) can take effect on a port at the same time.
Enabling TC-BPDU guard
When receiving topology change (TC) BPDUs (the BPDUs used to notify topology changes), a switch
flushes its forwarding address entries. If someone forges TC-BPDUs to attack the switch, the switch
will receive a large number of TC-BPDUs within a short time and be busy with forwarding address
entry flushing. This affects network stability.
With the TC-BPDU guard function, you can set the maximum number of immediate forwarding address
entry flushes that the switch can perform within a certain period of time after receiving the first
TC-BPDU. For TC-BPDUs received in excess of the limit, the switch performs forwarding address
entry flush only when the time period expires. This prevents frequent flushing of forwarding address
entries.
Follow these steps to enable TC-BPDU guard:
To do... Use the command... Remarks
Enter system view system-view —
Enable the TC-BPDU guard
function
stp tc-protection enable
Optional
Enabled by default
Configure the maximum number of
forwarding address entry flushes
that the device can perform within
a specific time period after it
receives the first TC-BPDU
stp tc-protection threshold
number
Optional
6 by default
It is not recommended to disable this feature.
Remotely Configuring MSTP for an ONU
An S7500E switch installed with an OLT card can work as an EPON OLT. In this case, you can
remotely configure MSTP for an ONU attached to the OLT in ONU port view, as shown in the table
below.
Note that:
An ONU port supports STP/RSTP/MSTP. However, an ONU port supports only MSTI 0 among all
MSTIs.