Can two electrical interfaces communicate normally when one interface is forcibly configured to work in full duplex mode and the other work in auto-negotiation mode

10

According to IEEE 802.3, when electrical interface A in auto-negotiation mode connects to electrical interface B that is forcibly configured to work in full duplex mode, the two interfaces can go Up. However, interface A starts to work in half-duplex mode, and interface B still works in full duplex mode. In this case, the interface working in half-duplex mode encounters error packets and packet loss due to collision of the physical link. Therefore, it is strongly recommended that you configure the interconnected electrical interfaces to work in the same mode. That is, enable auto-negotiation mode on both interfaces or configure the interfaces to work at the same speed and duplex mode by using the following commands:

system-view
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] undo negotiation auto
[HUAWEI-GigabitEthernet0/0/1] speed 100
[HUAWEI-GigabitEthernet0/0/1] duplex full

Other related questions:
Can two interface communicate with each other if one interface works in auto-negotiation mode and the other works in forcible mode
This configuration is not recommended. When this configuration is used, the interface working in auto-negotiation mode changes to half-duplex state according to the auto-negotiation requirements. This reduces the network utilization efficiency and may cause other problems. It is strongly recommended that the local and remote interfaces work in the same mode. That is, they both work in auto-negotiation mode or forcible mode.

How can packet loss be avoided when two interfaces at both ends of a link work in auto-negotiation mode and use the half-duplex mode
You can configure the local and remote devices to work in non-auto-negotiation mode, and set their duplex mode to full-duplex to avoid packet loss. The configuration is as follows: system-view [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] undo negotiation auto [HUAWEI-GigabitEthernet0/0/1] duplex full

Modify attributes of interfaces on the S1728GWR-4P switch
Modify the attributes (including the auto-negotiation mode, manual setting of port rate, full duplex mode, and traffic control) of an interface on an S1728GWR-4P switch using either of the following methods: 1. Port-based configuration: a. Choose Interface > Port > General. b. Select Configure by Port Range from the Action drop-down list box. Configure parameters of interfaces within a range in a batch. c. After completing the configuration, click Apply. The configuration takes effect immediately. To check status of each interface, choose Interface > Port > General and select Show Information from the Action drop-down list box.�?2. Port list based configuration: a. Choose Interface > Port > General. b. Select Configure by Port List from the Action drop-down list box. Configure parameters of each interface. c. After completing the configuration, click Apply. The configuration takes effect immediately. To check status of each interface, choose Interface > Port > General and select Show Information from the Action drop-down list box.

Can Ethernet interfaces be configured to work in half duplex mode
The following interfaces can work in half-duplex mode at the rate of 10 Mbit/s or 100 Mbit/s: FE electrical interfaces, GE electrical interfaces, and GE optical interfaces with GE copper modules installed

Rates on all interfaces working in auto-negotiation mode are different on a WLAN device
When all interfaces of a WLAN device work in auto-negotiation mode, the negotiated rate is the maximum rate supported by the interfaces. However, an interface may negotiate a rate of 100 Mbit/s with a peer interface, while other interfaces negotiate a rate of 1000 Mbit/s with peer interfaces. The possible cause is that the Ethernet cable connecting the GE interfaces on the local and peer devices cannot support a high working rate due to deterioration or RJ-45 connector faults. Therefore, the negotiated rate can only be 100 Mbit/s or 10 Mbit/s. In this case, replace the Ethernet cable.

If you have more questions, you can seek help from following ways:
To iKnow To Live Chat
Scroll to top