HP ProCurve 5400zl Series, Installation And Getting Started Manual

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5-3
Troubleshooting
Basic Troubleshooting Tips
Troubleshooting
■ Connecting to devices that have a fixed full-duplex configuration.
The RJ-45 ports on the 5400 zl switches are all 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 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 5400 zl switches behave in this way (in compliance with the
IEEE 802.3 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 communi-
cations between the switch and the device.
Ensure that all devices connected to the 5400 zl switches are configured
to auto negotiate, or are configured to connect at half duplex (all hubs are
configured this way, for example).
If necessary though, you can modify the configuration of the ports on the
5400 zl switches to match the configuration of the connected device. Use
the switch console, the web browser interface, or ProCurve Manager to
modify the port configuration.
■
Check the port configuration. A port on your 5400 zl switch may not
be operating as you expect because it has been put into a “blocking” state
by Spanning Tree, GVRP (automatic VLANs), or LACP (automatic
trunking). (Note that the normal operation of the Spanning Tree, GVRP,
and LACP features may put the port in a blocking state.) Or, the port just
may have been configured as disabled through software.
Use the switch console to determine the port’s configuration and verify
that there is not an improper or undesired configuration of any of the
switch features that may be affecting the port. See the
Management and
Configuration Guide
which is on the HP networking Web site. See page
5-1 for details.
For more information on possible network problems and their solutions, refer
to the technical note “Troubleshooting LAN Performance and Intermittent
Connectivity Problems”, which can be found on the HP networking Web site
in the Reference Library,
www.hp.com/networking/support , in the A-Z index
section.