HP J4865A Installation And Getting Started Manual page 53

Connecting to devices that have a fixed full-duplex configuration.
The RJ-45 ports on the Series 4100gl 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 Series 4100gl 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
communications between the switch and the device.
Ensure that all devices connected to the Series 4100gl 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
Series 4100gl Switches to match the configuration of the connected
device. Use the switch console, the web browser interface, or HP
ProCurve Manager for Hubs & Switches to modify the port configuration.
Check the port configuration. A port on your Series 4100gl 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
there is not an improper or undesired configuration of any of the switch
features that may be affecting the port. See the Management and Config
uration Guide that is on the documentation CD-ROM that came with your
switch for more information.
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 ProCurve web site,
http://www.hp.com/go/hpprocurve, in the Information Library section.
Troubleshooting
Basic Troubleshooting Tips
4-3