Configuration Guide User guide

670 FastIron Configuration Guide
53-1002494-02
Enabling the detection of PoE power requirements advertised through CDP
To re-enable support for legacy power consuming devices after it has been disabled, enter the
legacy-inline-power command (without the no parameter).
The <slotnum> variable is required on chassis devices when disabling or re-enabling legacy
support on a slot.
Use the show run command to view whether support for PoE legacy power consuming devices is
enabled or disabled.
Enabling the detection of PoE power requirements
advertised through CDP
Many power consuming devices, such as Cisco VoIP phones and other vendors’ devices, use the
Cisco Discovery Protocol (CDP) to advertise their power requirements to power sourcing devices,
such as Brocade PoE devices. Brocade power sourcing equipment is compatible with Cisco and
other vendors’ power consuming devices; they can detect and process power requirements for
these devices automatically.
NOTE
If you configure a port with a maximum power level or a power class for a power consuming device,
the power level or power class will take precedence over the CDP power requirement. Therefore, if
you want the device to adhere to the CDP power requirement, do not configure a power level or
power class on the port.
Command syntax for PoE power requirements
To enable the Brocade device to detect CDP power requirements, enter the following commands.
Brocade# configure terminal
Brocade(config)# cdp run
Syntax: [no] cdp run
Use the no form of the command to disable the detection of CDP power requirements.
Setting the maximum power level for a PoE power-
consuming device
When PoE is enabled on a port to which a power consuming device or PD is attached, by default, a
Brocade PoE device will supply 15.4 watts of power at the RJ-45 jack, minus any power loss
through the cables. A PoE+ device will supply either 15.4 or 30 watts of power (depending on the
type of PD connected to the port), minus any power loss through the cables. For example, a PoE
port with a default maximum power level of 15.4 watts will receive a maximum of 12.95 watts of
power after 2.45 watts of power loss through the cable. This is compliant with the IEEE 802.3af
and 802.3at specifications for delivering inline power. Devices that are configured to receive less
PoE power, for example, 4.0 watts of power, will experience a lower rate of power loss through the
cable.
If desired, you can manually configure the maximum amount of power that the Brocade PoE device
will supply at the RJ-45 jack.