More information about the Spanning Tree protocol is included in Appendix B.

Traffic Localization

The Bridge Module is a packet store-and-forward device that receives all packets and, if necessary, forwards them from the subnetwork on one side of the bridge to the subnetwork on the other side. The Bridge Module also acts as a packet filter, filtering packets based upon local destination addresses.

Filtering can isolate high traffic subnetworks from the rest of the LAN. For example, if the systems and servers in a cluster or subnetwork usually communicate with each other and rarely communicate with systems on other LANs, the Bridge Module does not forward that traffic to the extended LAN, except as needed.

The Bridge Module allows you to set up to 100 device addresses to be always forwarded to or never forwarded to. This can be used to keep sensitive subnetwork traffic local at all times. Enhanced network performance is also gained through the use of this feature.

Topology Switching

Topology switching enables you to automatically change the extended LAN topology without having to recable or take the network down. Bridging functionality lets you switch between any two ONline channels or between any ONline channel and an external Ethernet network. Topology switching is performed using the Bridge Module's command interface. The Bridge Module automatically recalculates the Spanning Tree to reorient the bridge in the network.

Automatic Address Learning

When attached to a subnetwork, the Bridge Module dynamically learnsthe addresses of all nodes on the subnetwork - thus it is called a learning

Introduction 1 - 5

Page 25
Image 25
3Com 5102B-EE installation and operation guide Traffic Localization, Automatic Address Learning, Topology Switching