Intelligent Power Management - Cisco Catalyst 4500 Series Configuration Manual

Power Management Modes
If you set a non-PoE-capable interface to automatically detect and apply power, an error message
Note
indicates that the configuration is not valid.
The following example shows how to set the Fast Ethernet interface 4/1 to automatically detect PoE and
send power through that interface, and to verify the PoE configuration:
Switch# configure terminal
Enter configuration commands, one per line.
Switch(config)# interface fastethernet 4/1
Switch(config-if)# power inline auto
Switch(config-if)# end
Switch# show power inline fastethernet 4/1
Available:677(w)
Interface Admin
--------- ------ ---------- ---------- ---------- ------------------- -----
Fa4/1
Interface
---------- --------------- --------------------
Fa4/1
Switch#
The following example shows how to configure an interface so that it never supplies power through the
interface:
Switch# configure terminal
Enter configuration commands, one per line.
Switch(config)# interface fastethernet 5/2
Switch(config-if)# power inline never
Switch(config-if)# end
Switch#

Intelligent Power Management

All Catalyst 4500 PoE-capable modules use Intelligent Power Management to provide power on each
interface. When a powered device (PD) is attached to a PoE-capable port, the port detects the PD and
provision power accordingly. If a Cisco PD is used, the switch and PD negotiate power using CDP
packets to determine the precise amount of power needed by the PD. If the PD is 802.3af compatible,
the difference between what is mandated by the 802.3af class and what is actually needed by the PD is
returned to the power budget for use by additional devices. In this way, power negotiation enables
customers to stretch their power budget and use it more effectively.
Power negotiation also enables the interoperability of newer Cisco powered devices with older legacy
PoE-capable ports from Cisco. Newer Cisco PDs do not consume more than what the switch port can
provide.
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
13-4
Used:11(w) Remaining:666(w)
Oper
From PS
auto on 11.2
AdminPowerMax AdminConsumption
(Watts) (Watts)
15.4
End with CNTL/Z.
Power(Watts) Device
To Device
10.0 Ieee PD
10.0
End with CNTL/Z.
Chapter 13 Configuring Power over Ethernet
Class
0
OL-25340-01