Cisco Catalyst 9300 Series, Hardware Installation Manual, Page: 60 / 132

10/100/1000/Multigigabit Ethernet Port Connections
The switch 10/100/1000 and Multigigabit Ethernet port configuration changes to operate at the speed of the
attached device. If the attached ports do not support autonegotiation, you can manually set the speed and
duplex parameters. Connecting devices that do not autonegotiate or that have the speed and duplex parameters
manually set can reduce performance or result in no linkage.
To maximize performance, choose one of these methods for configuring the Ethernet ports:
• Let the ports autonegotiate both speed and duplex.
• Set the interface speed and duplex parameters on both ends of the connection.
Auto-MDIX Connections
The autonegotiation and the auto-MDIX features are enabled by default on the switch.
With autonegotiation, the switch port configurations change to operate at the speed of the attached device. If
the attached device does not support autonegotiation, you can manually set the switch interface speed and
duplex parameters.
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 17: Recommended Ethernet Cables (When Auto-MDIX is Disabled)
Straight-Through Cable Crossover Cable Device
No Yes Switch to switch
No Yes Switch to hub
Yes No Switch to computer or server
Yes No Switch to router
Yes No Switch to IP phone
4
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 Cisco UPOE/UPOE+ Port Connections
The 10/100/1000/Multigigabit Ethernet PoE+ and Cisco UPOE/UPOE+ ports have the same autonegotiation
settings and cabling requirements that are described in the
10/100/1000/Multigigabit Ethernet Port Connections,
on page 48 . These ports can provide PoE, PoE+, or Cisco UPOE/UPOE+ 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.
Cisco Catalyst 9300 Series Switches Hardware Installation Guide
48
Installing a Switch
10/100/1000/Multigigabit Ethernet Port Connections