Unusual Network Activity; Diagnostic Tests - HP AdvanceStack Hub-16U Installation And Reference Manual

Troubleshooting
Non-standard Cables
Mis-wired cables may cause numerous network collisions, and can seriously
impair network performance. Before connecting cables into your network,
you should verify that they comply with the applicable standards. For a list
of compatible cables and a description of the pinouts for each port on the
hub (which can be used to confirm the compatibility of unlisted cables), see
appendix A, "Cables and Connectors".
Topology
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 trouble after recent changes to a network,
switch back to the previous topology. If you no longer have any trouble, the
new topology is probably at fault. Refer to the guide entitled Designing
HP AdvanceStack Workgroup Networks for topology configuration
guidelines. Contact your HP-authorized LAN dealer or local HP sales office
to get a copy of this guide.

Unusual Network Activity

Network activity that exceeds accepted norms often indicates a hardware
problem with one or more of the network components, possibly including
the hub. Unusual network activity is usually indicated by the LEDs on the
front of the hub or measured with one of the diagnostic tools in the ASCII
console software. Refer to "Diagnosing with LEDs" earlier in this chapter
for information on using LEDs to identify unusual network activity.

Diagnostic Tests

If you have an HP AdvanceStack 8U/16U SNMP module installed into the
hub, the ASCII console software or HP Interconnect Manager provides tests
and indicators that can be used to monitor the hub and its network
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