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the group may be changed dynamically as required. In order to utilize the ability to change
an aggregated port group, that is, to add or remove ports from the group, at least one of the
participating devices must designate LACP ports as active. Both devices must support
LACP.
“Passive” Port Role:
LACP ports that are designated as passive cannot initially send
LACP control frames. In order to allow the linked port group to negotiate adjustments and
make changes dynamically, one end of the connection must have “active” LACP ports.
4.4.4 Rapid Spanning Tree
The Spanning Tree Protocol (STP), defined in the IEEE Standard 802.1D, creates a
spanning tree within a mesh network of connected layer-2 bridges (typically Ethernet
switches) and disables the links which are not part of that tree, leaving a single active path
between any two network nodes.
Multiple active paths between network nodes cause a bridge loop. Bridge loops create
several problems. First, the MAC address table used by the switch or bridge can fail, since
the same MAC addresses (and hence the same network hosts) are seen on multiple ports.
Second, a broadcast storm occurs. This is caused by broadcast packets being forwarded in
an endless loop between switches. A broadcast storm can consume all available CPU
resources and bandwidth.
Spanning tree allows a network design to include spare (redundant) links to provide
automatic backup paths if an active link fails, without the danger of bridge loops, or the need
for manually enabling/disabling these backup links.
To provide faster spanning tree convergence after a topology change, an evolution of the
Spanning Tree Protocol: Rapid Spanning Tree Protocol (RSTP), introduced by IEEE with
document 802.1w. RSTP, is a refinement of STP; therefore, it shares most of its basic
operation characteristics. This essentially creates a cascading effect away from the root
bridge where each designated bridge proposes to its neighbors to determine if it can make a
rapid transition. This is one of the major elements which allow RSTP to achieve faster
convergence times than STP.
Click the folder
Rapid Spanning Tree
from the
Switch Management
menu and then three
options within this folder will be displayed as follows.
1. RSTP Switch Settings:
Set up system priority, max Age, hello time, etc.
Summary of Contents for FOS-3124 SERIES
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