Basic troubleshooting tips
The following situations cause most problems. Check for these items first when starting your
troubleshooting:
• Faulty or loose cables. Look for loose or faulty connections. If they appear to be OK, make sure that the
connections are snug. If that does not correct the problem, try a different cable.
• Non standard cables. Non standard and mis-wired cables may cause network collisions and other
network problems, and can seriously impair network performance. Use a new, correctly wired cable. For
pinouts and correctly wired cable, compare your cable to the cable information in the latest version of
the ArubaOS-Switch and ArubaOS Transceiver Guide at https://asp.arubanetworks.com/downloads. A
category 5 cable tester is a recommended tool for every 1000Base-T network installation.
• Improper Network Topologies. It is important to ensure that 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 likely at fault.
In addition, make sure that your network topology contains no data path loops. Between any two end
nodes, there must be only one active cabling path at any time. Data path loops cause broadcast storms
that severely impact your network performance.
Building redundant paths between important nodes in your network provides some fault tolerance.
Before opening redundant paths, enable Spanning Tree Protocol support on the switch. Spanning tree
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 or the web browser interface.
The 6400 switches also support Trunking (link aggregation), which allows using multiple network cables
for a single network connection without causing a data path loop. For more information, go to https://
asp.arubanetworks.com/downloads and see these publications:
◦
Spanning Tree: Layer 2 Bridging Guide
◦
Trunking: Link Aggregation Guide
• Using event and debug logs, show tech, and run-time diagnostics. These built-in features can help to
isolate the sources of problems. For more information, see the Diagnostics and Supportability Guide at
https://asp.arubanetworks.com/downloads.
Functions of the management module reset button
CAUTION: Use a hard reset on a management module only if other methods to recover from a
loss of control have failed. Using a hard reset can result in corrupting the file system on the
management module SSD (solid state drive). In this case, reformatting the management module
SSD is required to recover.
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Aruba 6400 Switch Series Installation and Getting Started
Guide
