Troubleshooting

Troubleshooting

Basic Troubleshooting Tips

■Improper Network Topologies. It is important to make sure you have a valid network topology. Common topology faults include excessive cable length and excessive repeater delays between end nodes. If you have network problems after recent changes to the network, change back to the previous topology. If you no longer experience the problems, the new topology is probably at fault. Sample topologies are shown at the end of chapter 2 in this book, and some topology configuration guidelines can be found online at the ProCurve Networking Web site, http://www.procurve.com.

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.

For your switch, 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 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 ProCurve Manager.

The Series 6400cl Switch devices also support Trunking, which allows multiple network cables to be used for a single network connection without causing a data path loop. For more information on Spanning Tree and Trunking, see the Management and Configuration Guide, which is on the Documentation CD-ROM that came with your switch.

■Check the port configuration. A port on your switch may not be operating as you expect because it has been put into a “blocking” state by Spanning Tree, meshing, or LACP (automatic trunking). (Note that the normal operation of the Spanning Tree, meshing, and LACP features may put the port in a blocking state.) Or, the port just may have been configured as disabled through software.

Use the switch console to determine the port’s configuration and verify that there is not an improper or undesired configuration of any of the switch features that may be affecting the port. For more information, see the Management and Configuration Guide, which is on the Documenta- tion CD-ROM that came with your switch.

For more information on possible network problems and their solutions, refer to the technical note “Troubleshooting LAN Performance and Intermittent Connectivity Problems”, which can be found on the ProCurve Networking Web site, http://www.procurve.com, in the Information Library section.

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