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Poe ports – Cisco 3560 User Manual

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Catalyst 3560 Switch Hardware Installation Guide

OL-6337-07

Chapter 1 Product Overview

Front Panel Description

When you connect the switch to workstations, servers, routers, and Cisco IP Phones, be sure that the
cable is a straight-through cable. When you connect the switch to switches or hubs, use a crossover
cable. When using a straight-through or crossover cable for 1000BASE-T connections, be sure to
use a twisted four-pair, Category 5 cable for proper operation. Pinouts for the cables are described
in

Appendix B, “Connector and Cable Specifications.”

You can use the mdix auto interface configuration command to enable the automatic
medium-dependent interface crossover (auto-MDIX) feature. When the feature is enabled, the
switch detects the required cable type for copper Ethernet connections and configures the interfaces
accordingly. Therefore, you can use either a crossover or a straight-through cable for connections
to a copper 10/100, 10/100/1000, or 1000BASE-T SFP module port on the switch, regardless of the
type of device on the other end of the connection.

The auto-MDIX feature is enabled by default on switches running Cisco IOS Release 12.2(18)SE or
later. For releases between Cisco IOS Release 12.1(14)EA1 and 12.2(18)SE, the auto-MDIX feature
is disabled by default. For configuration information for this feature, see the switch software
configuration guide or the switch command reference.

PoE Ports

The10/100 and 10/100/1000 PoE ports on the switch provide PoE support for devices compliant
with IEEE 802.3af and Cisco prestandard PoE support for Cisco IP Phones and Cisco Aironet
Access Points.

Each of the Catalyst 3560-8PC, 3560-12PC-S, 3560-24PS, and 3560V2-24PS switch 10/100 ports
or the Catalyst 3560G-24PS switch 10/100/1000 ports deliver up to 15.4 W of PoE.

On the Catalyst 3560-48PS, 3560G-48PS, and 3560V2-48PS switches, any 24 of the 48 10/100 or
10/100/1000 ports delivers 15.4 W of PoE, or any combination of the ports delivers an average of
7.7 W of PoE at the same time, up to a maximum power output of 370 W.

The Catalyst 3560-12PC-S switch delivers a maximum power output of approximately 125 W total
PoE power.

On a per-port basis, you can control whether or not a PoE port automatically provides power when
an IP phone or an access point is connected. The device manager, Network Assistant, and the CLI
provide PoE settings for each 10/100 or 10/100/1000 PoE port:

Auto: When you select the Auto setting, the port provides power only if a valid powered device,
such as an IEEE 802.3af-compliant powered device, a Cisco prestandard IP phone, or a Cisco
prestandard Cisco access point, is connected. The Auto setting is the default.

Never: When you select the Never setting, the port does not provide power even if a Cisco
IP phone or an access point is connected.

You can connect a Cisco IP Phone or Cisco Aironet Access Point to a Catalyst 3560 PoE switch
10/100 or 10/100/1000 port and to an AC power source for redundant power. The powered device
might change to the AC power source as its primary power source when connected to it. In that case,
the PoE port becomes the backup power source for the powered device.

If the primary source fails, the second power source becomes the primary power source to the
powered device. During the power transfer, an IP phone might reboot or reestablish link with the
switch.

For information about configuring and monitoring PoE ports, see the switch software
configuration guide. For information about Cisco IP Phones and Cisco Aironet Access Points, see the
documentation that came with your IP phone or access point.