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Using the Business Policy Switch 2000 Version 1.2
Refer to Virtual Local Area Networks (VLANs) on page63 for a more
complete description of VLANs. For information on configuring VLANs, refer to
Chapters 2 and 3, Using Web-based Management for the Business Policy Switch
2000 Software Version 1.2, Reference for the Business Policy Switch 2000
Management Software Version 1.2, and Reference for the Business Policy Switch
2000 Command Line Interface Software Version 1.2.
Multiple Spanning Tree Protocol groups
BPS 2000 switches support the Spanning Tree Protocol (STP) as defined in IEEE
802.1D. As defined in the IEEE 802.1D standard, the Spanning Tree Protocol
detects andeliminates logical loops in a bridged or switched network. When
multiple paths exist, the spanning tree algo rithm configures the network so that a
bridge or switch uses only the most efficient path. If that path fails, the protocol
automatically reconfigures the network to make another path become active, thus
sustaining network operations.
Starting with software version 1.2, the BPS 2000 supports multiple spanning tree
groups (STGs). The BPS 2000 supports a maximum of 8 STGs, either all in one
standalone switch or across a stack consisting of only BPS 2000 switches (Pure
BPS 2000 Stack mode). Multiple STGs provide multiple data paths, which can be
used for load-balancing and redundancy. You enable load balancing between two
BPS 2000 switches using multiple STGs by configuring each path with a di f fere nt
VLAN and then assigning each VLAN to a separate STG. Each STG is
independent. Each STG sends its own Bridge Protocol Data Units (BPDUs), and
each STG must be independently configured.
To use more that one STG, ensure that the Stack Operational Mode is set to Pure
BPS 2000 Stack mode. To view and set the Stack Operational Mode, refer to
Chapter 3, Using Web-based Management for the Business Policy Switch 2000
Software Version 1.2, or Refer e nce fo r t he Busi ness Pol icy Swit ch 2000 Comman d
Line Interface Software Version 1.2.You have only the single default STG
available if you are in Hybrid Stack mode, which is for running mixed stacks.