HP ProCurve 2224 Installation Manual page 32

Troubleshooting
Basic Troubleshooting Tips
3-2
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
numerous network collisions and other network problems, and can seri-
ously impair network performance. Use a new correctly-wired cable or
compare your cable to the cable in appendix B, "Cables and Connectors"
for pinouts and correct cable wiring. A category 5 cable tester is a
recommended tool for every 100Base-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 too many repeaters (hubs) 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. Refer to the Network Design Guide for
topology configuration guidelines. This guide can be found online at the
HP World Wide Web site for networking products, http://www.hp.com/go/
procurve. You can find it quickly by searching for "Network Design
Guide".
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.