Troubleshooting
Troubleshooting
Solutions to Common Problems
cable in appendix A, “Cables and Connectors” for pinouts and correct cable wiring. A category 5 cable tester is a recommended tool for every
■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 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 guide entitled Designing HP AdvanceStack Workgroup Networks for topology configuration guide- lines. This guide is included on the HP AdvanceStack Products
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 install a Switch 208/224 Manage- ment Module and 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.
■Switch
For the Switch 208T and 224T, there are a few specific network connec- tion situations you must avoid:
•Wrong transceiver type
•Wrong network speed connected -- You have connected a
10 Mbit/s cable to one of the 100 Mbit/s ports. On the Switch 208/224, the 100 Mbit/s ports cannot operate at 10 Mbit/s.
•Expansion Module installed
disabled, as shown by the port 1 disabled LED on the front of the
switch 
.