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Configuring bpdu dropping, Configuration prerequisites, Configuration procedure – H3C Technologies H3C S3100 Series Switches User Manual

Page 258: Configuration example

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# Set the maximum times for the switch to remove the MAC address table and ARP entries within 10
seconds to 5.

system-view

[Sysname] stp tc-protection threshold 5

Configuring BPDU Dropping

In a STP-enabled network, attackers may send BPDUs to switches continuously in order to destroy the
network. When a switch receives BPDUs, it will forward them to other switches. As a result, STP
calculation is performed repeatedly, which may occupy too much CPU of the switches or cause errors in
the protocol state of the BPDUs.

To address this threat, you can enable BPDU dropping on Ethernet ports of the switches. With BPDU
dropping enabled, a port will not receive or forward any BPDUs. In this way, switches are protected
against forged BPDU attacks, thus ensuring correct STP calculation.

z

You can enable BPDU dropping on ports that need not receive or forward BPDUs, for example,
edge ports.

z

Currently, only S3100-EI series Ethernet Switches support the BPDU Dropping feature.

Configuration Prerequisites

MSTP runs normally on the switch.

Configuration procedure

Follow these steps to configure BPDU dropping:

To do...

Use the command...

Remarks

Enter system view

system-view

Enter Ethernet port view

interface

interface-name

Enable BPDU dropping

bpdu-drop any

Required
BPDU dropping is disabled by
default.

Configuration example

# Enable BPDU dropping on Ethernet 1/0/1.

system-view

[Sysname] interface Ethernet 1/0/1

[Sysname-Ethernet1/0/1] bpdu-drop any