TP-Link TL-SG3424P manual STP Security, Port Protect

Note:

The port status of one port in different spanning tree instances can be different.

Global configuration Procedure for Spanning Tree function:

Step	Operation					Description
1	Make clear roles the switches					Preparation.
	play	in	spanning		tree
	instances:		root	bridge	or
	designated bridge
2	Globally		configure MSTP			Required. Enable Spanning Tree function on the switch
	parameters					and	configure	MSTP	parameters	on	Spanning
						Tree→STP Config→STP Config page.
3	Configure		MSTP	parameters		Required. Configure MSTP parameters for ports on
	for ports					Spanning Tree→Port Config→Port Config page.
4	Configure the MST region					Required. Create MST region and configure the role the
						switch	plays	in the	MST region	on	Spanning
						Tree→MSTP Instance→Region Config and Instance
						Config page.
5	Configure		MSTP	parameters		Optional. Configure different instances in the MST region
	for instance ports					and configure MSTP parameters for instance ports on
						Spanning Tree→MSTP Instance→Instance Port
						Config page.

7.4 STP Security

Configuring protection function for devices can prevent devices from any malicious attack against STP features. The STP Security function can be implemented on Port Protect and TC Protect pages.

Port Protect function is to prevent the devices from any malicious attack against STP features.

7.4.1 Port Protect

On this page you can configure loop protect feature, root protect feature, TC protect feature, BPDU protect feature and BPDU filter feature for ports. You are suggested to enable corresponding protection feature for the qualified ports.

¾Loop Protect

In a stable network, a switch maintains the states of ports by receiving and processing BPDU packets from the upstream switch. However, when link congestions or link failures occurred to the network, a down stream switch does not receive BPDU packets for certain period, which results in spanning trees being regenerated and roles of ports being reselected, and causes the blocked ports to transit to forwarding state. Therefore, loops may be incurred in the network.

The loop protect function can suppresses loops. With this function enabled, a port, regardless of the role it plays in instances, is always set to blocking state, when the port does not receive BPDU packets from the upstream switch and spanning trees are regenerated, and thereby loops can be prevented.

¾Root Protect

A CIST and its secondary root bridges are usually located in the high-bandwidth core region.

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