Management and Configuration Guide K/KA/KB.15.15

threshold 75
(HP_Switch_name#) power-over-ethernet slot b
threshold 68
The last threshold command affecting a given slot supersedes the previous threshold command
affecting the same slot. Thus, executing the following two commands in the order shown sets the
threshold for the PoE module in slot "D" to 75%, but leaves the thresholds for any PoE modules in
the other slots at 90%:
(HP_Switch_name#) power-over-ethernet
threshold 90
(HP_Switch_name#) power-over-ethernet slot d
threshold 75
(If you reverse the order of the above two commands, all PoE modules in the switch will have a
threshold of 90%.)
Without the [slot slot-id-range] option, the switch applies one power threshold setting on
all PoE modules installed in the switch.
About PoE/PoE+ allocation using LLDP information
LLDP with PoE
When using PoE, enabling poe-lldp-detect allows automatic power configuration if the link
partner supports PoE. When LLDP is enabled, the information about the power usage of the PD is
available, and the switch can then comply with or ignore this information. You can configure PoE
on each port according to the PD (IP phone, wireless device, and so on) specified in the LLDP field.
The default configuration is for PoE information to be ignored if detected through LLDP.
NOTE: Detecting PoE information via LLDP affects only power delivery; it does not affect normal
Ethernet connectivity.
LLDP with PoE+
Overview
The DLC for PoE provides more exact control over the power requirement between a PSE and PD.
The DLC works in conjunction with the PLC and is mandatory for any Type-2 PD that requires more
than 12.95 watts of input power.
NOTE: DLC is defined as part of the IEEE 802.3at standard.
You can implement the power negotiation between a PSE and a PD at the physical layer or at the
data link layer. After the link is powered at the physical layer, the PSE can use LLDP to query the
PD repeatedly to discover the power needs of the PD. Communication over the data link layer
allows finer control of power allotment, which makes it possible for the PSE to supply dynamically
the power levels needed by the PD. Using LLDP is optional for the PSE but mandatory for a Type
2 PD that requires more than 12.95 watts of power.
If the power needed by the PD is not available, that port is shut off.
PoE allocation
There are two ways LLDP can negotiate power with a PD:
• Using LLDP MED TLVs
Disabled by default. Can be enabled using the
int <port-list> PoE-lldp-detect [ enabled | disabled ]
command, as shown below.
128 Power Over Ethernet (PoE/PoE+) Operation