22.4.4 Speed and Full/Half Duplex Settings

In the following cases, set the line speed and full-duplex/half-duplex for each port as required.

10BASE-T/100BASE-TX/1000BASE-T
Use SFP-T or SFP(1000BASE-X) on SFP
Use SFP-T or SFP on SFP+/SFP Shared Ports

Auto-negotiation is used by default. If you want to use a fixed connection without auto-negotiation, configure the line speed and full-duplex/half-duplex. If you are connecting with a fixed setting, you must make a fixed setting for both speed command and duplex command. If the correct combination is not set, it will operate by default.

In the following cases, the setting is not necessary because the line speed and full duplex are fixed for each interface.

Use SFP+ on SFP+/SFP shared ports

<Structure of this section>

(1) When the line speed and full-duplex/half-duplex are fixed and connected to the remote device

Points to note

If auto-negotiation is not used, specify the line speed and full-duplex/half-duplex, and connect using the fixed settings. This section describes the settings for connecting to the remote device using 1000Mbit/s full-duplex (fixed) on 1000BASE-X port.

When setting the line speed to 1000Mbit/s, be sure to set it to full duplex.

Command examples

(config)# interface gigabitethernet 1/0/1

(config-if)# shutdown

(config-if)# speed 1000

(config-if)# duplex full

Shut down the Ethernet interface and connect it to the remote device using 1000Mbit/s full-duplex connection.
(config-if)# no shutdown

Releases the Ethernet interface from the shutdown status.

(2) When connecting to an external device that does not support auto-negotiation

Points to note

Depending on the remote device, 10BASE-T or 100BASE-TX connection sometimes cannot be established by auto-negotiation. In this case, specify the line speed and full duplex/half duplex according to the remote device, and connect using the fixed settings.

This section describes the settings for connecting to an external device with 10BASE-T half-duplex fixed.

Command examples

(config)# interface gigabitethernet 1/0/10

(config-if)# shutdown

(config-if)# speed 10

(config-if)# duplex half

Shut down the Ethernet interface and connect it to the remote device using 10BASE-T half-duplex.
(config-if)# no shutdown

Releases the Ethernet interface from the shutdown status.

(3) When auto-negotiation also uses a specific speed to connect to the remote device

Points to note

For the Switch, you can set a specific transmission speed even when auto-negotiation is used for a connection. Note that if auto-negotiation is used and a specific transmission speed is also specified, even if a connection with auto-negotiation is successful, the status of the line is not link-up unless the set transmission speed is assured. This eliminates the risk of the line being connected at an unexpected transmission speed.

This section explains how to set the line speed with 1000Mbit/s and connect to the remote device even when auto-negotiation is used.

Command examples

(config)# interface gigabitethernet 1/0/10

(config-if)# shutdown

(config-if)# speed auto 1000

Even if the Ethernet interface is shut down and auto-negotiation is used to connect to the remote device, the line speed is set to connect using only 1000Mbit/s.
(config-if)# no shutdown

Releases the Ethernet interface from the shutdown status.