AMS Quick Install Guide
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7. Troubleshooting
Basic Troubleshooting Tips
Most problems are caused by the following situations. Check for these items first when starting your
troubleshooting:
Connecting to devices that have a fixed full- duplex configuration.
The RJ-45 ports are configured as “Auto”. That is, when connecting to attached devices, the switch
will operate in one of two ways to determine the link speed and the communication mode (half
duplex or full duplex):
If the connected device is also configured to Auto, the switch will automatically negotiate
both link speed and communication mode.
If the connected device has a fixed configuration, for example 100Mbps, at half or full
duplex, the switch will automatically sense the link speed, but will default to a
communication mode of half duplex.
Because the APS Series switches behave in this way (in compliance with the IEEE802.3 standard), if a
device connected to the switch has a fixed configuration at full duplex, the device will not connect
correctly to the switch. The result will be high error rates and very inefficient communications
between the switch and the device.
Make sure all devices connected to the APS Series switches are configured to auto negotiate, or are
configured to connect at half duplex (all hubs are configured this way, for example).
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 or incorrectly wired cables may cause network collisions and other network problems,
and can seriously impair network performance. Use a new correctly wired cable. For pin outs and
correct cable wiring a category 5 cable tester, is a recommended tool for every 100Base-TX and
1000Base-T network installation.
Incorrect Network Topologies.
It is important to make sure you have a valid network 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.
