HP ProCurve 4000M Installation Manual page 39

Troubleshooting
Basic Troubleshooting Tips
In addition, you should make sure that your network topology contains
no data path loops. Between any two end nodes, there should be only one
active cabling path at any time. Data path loops will cause broadcast
storms that will severely impact your network performance.
If you wish to build redundant paths between important nodes in your
network to provide some fault tolerance, you should enable Spanning
Tree Protocol support on the switch. This ensures that only one of the
redundant paths is active at any time, thus avoiding data path loops.
Spanning Tree can be enabled through the switch console, the web
browser interface, or HP TopTools for Hubs and Switches.
The Switch 8000M also supports Switch Meshing which allows multiple
data paths though a switched network to be active simultaneously for
enhanced network bandwidth. See the Management and Configuration
Guide that came with your switch for more information on Spanning Tree
and on Switch Meshing.
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