Solving Power Issues - 3Com Baseline 2226-PWR Plus User Manual

A PoE device is plugged in, but the PoE LED for
the port is off.
If a device is not supplied with power after you have
connected it to the Switch 2226-PWR Plus, check the
following:
The power budget for the Switch (180 watts) has
■
not been exceeded.
The cable used to connect to the device is in good
■
shape and is a Cat 5 or above grade.
The device is Power over Ethernet compliant and is
■
configured to receive Power over Ethernet. See the
documentation supplied with your device.
You are using ports 1 to 24.
■
The Link/Activity LED is on, but network perfor-
mance is poor .
The Switch supports full-duplex autonegotiation. If
the connected device does not support autonegotia-
tion, ensure that it is configured for half-duplex oper-
ation only. If the connected device has
autonegotiation disabled or overridden, and is config-
ured as full-duplex, the Switch will configure the link
as half-duplex, causing a mismatch that will reduce
network performance when data is transmitting and
receiving simultaneously on the same link.
Ensure that the connected device has either:
Autonegotiation enabled, or
■
The ports are configured for half-duplex operation
■
All ports appear to show continual activity.
There may be broadcast storms on the network.
Remove port connections one at a time, waiting a
few seconds between each port. If the LEDs go off
after removing a port connection, the device that was
connected to that port is introducing an excessive
amount of broadcast frames to the network. Some
pieces of network equipment operate by sending out
broadcast frames regularly.
Refer to the documentation that accompanies the
device for information on disabling the broadcast
operation.

Solving Power Issues

A device is connected to the Switch, but power
is not being supplied.
If power is not being supplied to a device connected
to the Switch, you should do the following checks:
Verify that the device is compliant with the
■
802.3af standard ref. [18].
The Switch will only supply power through the 24
■
front panel ports to 802.3af compliant devices.
Verify that the power budget for the Switch has
■
not been exceeded.
If the power budget has been exceeded, then by
default, the powered device connected to the PoE
port with the lowest priority port will lose power.
However, if all the devices connected to the Switch
have equal priority levels, then the port with the high-
est number will lose power.
Solving Power Issues 53