Operation Manual

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multi-optional.
Port:
Displays the port number of the switch.
Loop Protect: Loop Protect is to prevent the loops in the network brought by
recalculating STP because of link failures and network congestions.
Root Protect: Root Protect is to prevent wrong network topology change caused
by the role change of the current legal root bridge.
TC Protect: TC Protect
is to prevent the decrease of the performance and
stability of the switch brought by continuously removing MAC
address entries upon receiving TC-BPDUs in the STP network.
BPDU Protect: BPDU Protect is to prevent the edge port from being attacked by
maliciously created BPDUs
BPDU Filter:
BPDU Filter is to prevent BPDUs flood in the STP network.
LAG:
Displays the LAG number which the port belongs to.
7.4.2 TC Protect
When TC Protect is enabled for the port on Port Protect page, the TC threshold and TC protect
cycle need to be configured on this page.
Choose the menu Spanning Tree→STP Security→TC Protect to load the following page.
Figure 7-11 TC Protect
The following entries are displayed on this screen:

TC Protect
TC Threshold:
Enter a number from 1 to 100. It is the maximum number of the
TC-
BPDUs received by the switch in a TC Protect Cycle. The default
value is 20.
TC Protect Cycle:
Enter a value from 1 to 10 to specify the TC Protect Cycle. The
default value is 5.
7.5 Application Example for STP Function
 Network Requirements
 Switch A, B, C, D and E all support MSTP function.
 A is the central switch.
 B and C are switches in the convergence layer. D, E and F are switches in the access layer.