With auto-MDIX, the switch detects the required cable type for copper Ethernet connections and configures
the interface accordingly.
If auto-MDIX is disabled, use the guidelines in this table to select the correct cable.
Table 9: Recommended Ethernet Cables (When Auto-MDIX is Disabled)
Straight-Through CableCrossover CableDevice
NoYesSwitch to switch
NoYesSwitch to hub
YesNoSwitch to computer or server
YesNoSwitch to router
YesNoSwitch to IP phone
2
100BASE-TX and 1000BASE-T traffic requires twisted four-pair, Category 5 or higher. 10BASE-T
traffic can use Category 3 cable or higher.
PoE and POE+ Port Connections
The 10/100/1000 PoE and PoE+ ports have the same autonegotiation settings and cabling requirements that
are described in the 10/100/1000 Ports, on page 3. These ports can provide PoE and PoE+ inline power.
PoE inline power supports devices compliant with the IEEE 802.3af standard, as well as prestandard Cisco
IP Phones and Cisco Aironet Access Points. Each port can deliver up to 15.4 W of PoE. PoE+ inline power
supports devices compliant with the IEEE 802.3at standard, by delivering up to 30 W of PoE+ power per port
to all switch ports.
See Power Supply Modules, on page 8 for the power supply modules required to support PoE and PoE+ on
24- and 48-port switches.
Voltages that present a shock hazard may exist on Power over Ethernet (PoE) circuits if interconnections are
made using uninsulated exposed metal contacts, conductors, or terminals. Avoid using such interconnection
methods, unless the exposed metal parts are located within a restricted access location and users and service
people who are authorized within the restricted access location are made aware of the hazard. A restricted
access area can be accessed only through the use of a special tool, lock and key or other means of security.
Statement 1072
Warning
Voice over IP (VoIP) service and the emergency calling service do not function if power fails or is disrupted.
After power is restored, you might have to reset or reconfigure equipment to regain access to VoIP and the
emergency calling service. In the USA, this emergency number is 911. You need to be aware of the emergency
number in your country. Statement 371
Warning
Cisco Catalyst 9200 Series Switches Hardware Installation Guide
28
Installing the Switch
PoE and POE+ Port Connections