Normally these ports do not receive BPDUs, but if a user maliciously attacks the switch by sending
BPDUs, network topology jitter occurs.
To prevent this attack, MSTP provides BPDU protect function. With this function enabled on the
switch, the switch shuts down the edge ports that receive BPDUs and reports these cases to the
administrator. If a port is shut down, only the administrator can restore it.
BPDU Filter
BPDU filter function is to prevent BPDUs flood in the STP network. If a switch receives malicious
BPDUs, it forwards these BPDUs to the other switched in the network, which may result in
spanning trees being continuously regenerated. In this case, the switch occupying too much CPU
or the protocol status of BPDUs is wrong.
With BPDU filter function enabled, a port does not receive or forward BPDUs, but it sends out its
own BPDUs. Such a mechanism prevents the switch from being attacked by BPDUs so as to
guarantee generation the spanning trees correct.
Choose the menu Spanning Tree → STP Security → Port Protect to load the following page.
Figure 7-10 Port Protect
The following entries are displayed on this screen:
Port Protect
Port Select: Click the Select button to quick-
select the corresponding port based
on the port number you entered.
Select:
Select the desired port for port protect configuration. It is
multi-optional.
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