Auto-Mdix Connections; Poe+ And Cisco Upoe Port Connections - Cisco Catalyst C3850 Series Hardware Installation Manual

Auto-MDIX Connections

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 19: Recommended Ethernet Cables (When Auto-MDIX is Disabled)
Device
Switch to switch
Switch to hub
Switch to computer or server
Switch to router
Switch to IP phone
12

PoE+ and Cisco UPOE Port Connections

The 10/100/1000/Multigigabit Ethernet PoE+ and Cisco UPOE ports have the same autonegotiation settings
and cabling requirements that are described in the
page
Note Be careful when connecting a "snagless" Ethernet cable to port 1 on a 48-port switch. The protective boot of
the cable might inadvertently press the Mode button, which might cause the switch to erase its startup
configuration and reboot. See this field notice for more information:
docs/field-notices/636/fn63697.html
This issue does not occur if you are using Cisco IOS XE Release 3E or later releases.
Catalyst 3850 Switch Hardware Installation Guide
50
100BASE-TX and 1000BASE-T traffic requires twisted four-pair, Category 5 or higher. 10BASE-T
traffic can use Category 3 cable or higher.
49. These ports can provide PoE, PoE+, or Cisco UPOE inline power.
Crossover Cable
Yes
Yes
No
No
No
10/100/1000/Multigigabit Ethernet Port Connections, on
Switch Installation
Straight-Through Cable
No
No
Yes
Yes
Yes
http://www.cisco.com/c/en/us/support/
OL-26779-05