HP Aruba 3810M Series Installation And Getting Started Manual page 72

Tip
7 The port or remote link partner may be improperly
configured, or the port may be in a "blocking" state by
72 Troubleshooting
Problem Solution
NOTE: If the switch port configuration is
changed to one of the fixed configuration
options (for example, 100 Mbps/Full Duplex),
then the port operates as MDI-X only and you
must use the correct type of cable for the
connection. In general, for connecting an end
node (MDI port) to the switch, use
straight-through cable; for connecting to MDI-X
ports on hubs, other switches, and routers, use
crossover cable.
◦
For fiber-optic connections, verify the transmit
port on the switch is connected to the receive
port on the connected device, and the switch
receive port is connected to the transmit port on
the connected device.
For 1000Base-T connections, verify that the network
cabling complies with the IEEE 802.3ab standard.
the cable should be installed according to the
ANSI/TIA/EIA-568-A-5 specifications. Cable testing
should comply with the stated limitations for
Attenuation, Near-End Crosstalk, Far-End Crosstalk,
Equal-Level Far-End Crosstalk (ELFEXT), Multiple
Disturber ELFEXT, and Return Loss.
The cable verification process must include all patch
cables from any end devices, including the switch,
to any patch panels in the cabling path.
Verify the port has not been disabled through a
switch configuration change.
You can use the console interface, or, if you have
configured an IP address on the switch, use the web
browser interface, or IMC network management
software to determine the state of the port and
re-enable the port if necessary.
Verify the switch port configuration matches the
configuration of the attached device. For example,
if the switch port is configured as "Auto", the port on
the attached device also MUST be configured as
"Auto". Depending on the port type, twisted-pair or
fiber-optic, if the configurations don't match, the
results could be a very unreliable connection, or no
link at all.
If the other procedures don't resolve the problem,
try using a different port or a different cable.
You must ensure that the device at the other end of
the connection indicates a good link to the switch.