Port; Chapter 8 Port; Overview; What You Need To Know - ZyXEL Communications XGS1250-12 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 the
transmission speed and flow control on a port.

8.1.1 What You Need to Know

Read this section to know more about Loop Detection, Loop Prevention, and Broadcast Storm Control.
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 19 for more information about LEDs.
8.1.1.2 Broadcast Storm Control
Broadcast storm control limits the number of broadcast packets the Switch receives per second on the
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Port

Section 3.4 on