Basic Troubleshooting Tips - HP ProCurve 4202vl-48G Installation And Getting Started Manual

Troubleshooting

Basic Troubleshooting Tips

Basic Troubleshooting Tips
Most problems are caused by the following situations. Check for these items
first when starting your troubleshooting:
■
■
■
4-2
Faulty or loose cables. Look for loose or obviously faulty connections.
If they appear to be OK, make sure the connections are snug. If that does
not correct the problem, try a different cable.
Non-standard cables. Non-standard and miswired cables may cause
network collisions and other network problems, and can seriously impair
network performance. Use a new correctly-wired cable or compare your
cable to the cable in appendix B, "Switch Ports and Network Cables" for
pinouts and correct cable wiring. A category 5 cable tester is a recom-
mended tool for every 100Base-TX and 1000Base-T network installation.
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.
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.
With your Switch 4200vl Series, if you wish to build redundant paths
between important nodes in your network to provide some fault toler-
ance, 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 ProCurve Manager.
The Switch 4200vl Series also support Trunking, which allows multiple
network cables to be used for a single network connection without
causing a data path loop. See the Management and Configuration Guide
for your switch, available on the ProCurve Web site, for more information
on Spanning Tree and on Trunking.