Installation guide

Chapter 2 Switch Installation
Connecting to the 10/100 and 10/100/1000 Ports
2-50
Catalyst 3750 Switch Hardware Installation Guide
OL-6336-01
Note You can use the mdix auto interface configuration command in the CLI to enable
the automatic medium-dependent interface crossover (Auto-MDIX) feature.
When the Auto-MDIX 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.
Follow these steps to connect to 10BASE-T, 100BASE-TX or 1000BASE-T
devices:
Caution PoE faults are caused when noncompliant cabling or powered devices are
connected to a PoE port. Only standard-compliant cabling can be used to connect
Cisco pre-standard IP Phones and wireless access points or
IEEE 802.3af-compliant devices to PoE ports. A cable or device that causes a
PoE fault must be removed from the network.
Step 1 When connecting to workstations, servers, routers, and Cisco IP Phones, connect
a straight-through cable to an RJ-45 connector on the front panel. (See
Figure 2-44.) When connecting to switches or repeaters, use a crossover cable.
(See the “Cable and Adapter Specifications” section on page B-5 for cable-pinout
descriptions.)
Note When connecting to 1000BASE-T-compatible devices, be sure to use a
twisted four-pair, Category 5 cable.