Configuring a Working Mode for an Ethernet Interface
An Ethernet interface works in either half-duplex or full-duplex mode at the physical layer of an Ethernet network. To ensure communication between devices, configure a proper duplex mode for an Ethernet interface.
Context
On a large-scale Ethernet network, manually setting the interface rate and duplex mode, verifying device configurations, and checking Ethernet interface statistics are time-consuming. Manually setting the interface rate and duplex mode is recommended only when auto-negotiation of an Ethernet link fails. When there is an auto-negotiation problem, you are advised to upgrade device software or hardware for the device to support the auto-negotiation mechanism defined in IEEE 802.3u/z.
Perform the following steps on each router:
Procedure
- Run system-view
The system view is displayed.
- Run interface gigabitethernet interface-number
The Ethernet interface view is displayed.
- Run either of the following commands:
To configure a working mode for the Ethernet interface, run the duplex { full | half | auto } command.
To configure the Ethernet interface to work in auto-negotiation mode, run the negotiation auto command.
- Ethernet optical interfaces work only in full-duplex mode.
- When connecting to a hub, an Ethernet electrical interface on the router must work in half-duplex mode because the hub can work only in this mode. When connecting to a LAN switch, an Ethernet electrical interface on the router can work in either full-duplex or half-duplex mode. Ethernet electrical interfaces on the router and peer device must work in the same mode.
- If the working rate of a GE electrical interface is 1000 Mbit/s, you cannot configure the GE electrical interface to work in half-duplex mode.
- If the working rate of a GE electrical interface is 1000 Mbit/s and auto-negotiation is enabled, you cannot configure the GE electrical interface to work in half-duplex or full-duplex mode. In addition, you cannot disable auto-negotiation on the interface.
- If the working rate of a GE electrical interface is 10 Mbit/s or 100 Mbit/s, you can configure the interface to work in half-duplex mode and auto-negotiation mode.
- The rate of a 50|100GE interface can be adjusted using the switch mode command.
- Run commit
The configuration is committed.