HP J4897A, Installation Manual

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Troubleshooting
This chapter describes how to troubleshoot your Series 2700 Switch including
the following:
■ basic troubleshooting tips (page 3-1)
■
diagnosing with the LEDs (page 3-3)
■ hardware diagnostic tests (page 3-4)
■
HP Customer Support Services (page 3-5)
Basic Troubleshooting Tips
Most problems are caused by the following situations. Check for these items
first when starting your troubleshooting:
■
Connecting the RJ-45 ports to devices that have a fixed full-duplex
configuration
. The Series 2700 Switch 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 commu-
nication 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 100
Mbps, at half or full duplex, the switch will automatically sense the
link speed, but will default to a communication of
half duplex
Because the Series 2700 Switches behave in this way ( in compliance with
the IEEE 802.3 standard
), if a device connected to the switch RJ-45 ports
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 that all devices connected to the Series 2700 Switches’ RJ-45
ports are configured to auto negotiate, or are configured to connect at half
duplex (all hubs are configured this way, for example).
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