Port; Chapter 8 Port; Overview; What You Need To Know - ZyXEL Communications GS1200 Series User Manual

8.1 Overview

This chapter introduces and shows you how to configure the broadcast storm control feature and use
loop prevention or loop detection to prevent loops in your network. In addition, you can configure
transmission speed, flow control, port isolation, bandwidth control, and PoE on a port.

8.1.1 What You Need to Know

Read this section to know more about Loop Detection, Loop Prevention, Broadcast Storm Control, Port
Isolation, Bandwidth Control, and PoE.
8.1.1.1 Loop Detection and Loop Prevention
A switch loop happens if there is more than one connection between two ports on the same switch or
between two switches connected together. If this happens, broadcasts are continually rebroadcast
and could flood the network. You must break the loop by stopping multiple paths between two switch
ports.
Figure 30 The Switch Has Two Ports Connected with the Same Cable
Figure 31 The Connected Switch Has Two Ports Connected with the Same Cable
Figure 32 Two Connections between Switches without using the Spanning Tree Protocol (STP)
Loop Detection allows the Switch to discover a loop if it happens, and create a log. Loop Prevention
allows the Switch to shut down a port automatically if it discover a loop on that port. See
page 18 for more information about LEDs.

Chapter 8 Port

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Port

Section 3.3 on