Routing and switching

This is called a duplex mismatch , It is a condition where two connected devices operate in different duplex modes, that is, one operates in half duplex while the other one operates in full duplex. The effect of a duplex mismatch is a link that operates inefficiently. Duplex mismatch may be caused by manually setting two connected network interfaces at different duplex modes or by connecting a device that performs autonegotiation to one that is manually set to a full duplex mode.^[1]

Hi @emmaodenyire!

When the duplex modes of the two ports are inconsistent, packet loss or even link disconnection will occurs during data transmission. You can run the negotiation auto command to set the interfaces at both ends to work in auto-negotiation mode. After the negotiation succeeds, the devices at both ends of the link are locked in the same duplex mode and interface rate.

If the negotiation fails, you can manually change the duplex mode of the port to ensure that the duplex modes of the ports at both ends of the link are the same.

You can refer to the below link:

https://support.huawei.com/enterprise/en/doc/EDOC1000142060/7559ec6f?idPath=24030814|.

Hope it helps!

Hello friend,

Regardless of whether one side is half-duplex or full-duplex, the other side needs to be set to auto-negotiation so that it can work properly. However, it is mandatory that one side is half-duplex and the other is full-duplex. The full-duplex side does not perform collision detection and keeps sending data, but the half-duplex is always detected. The link is never idle and the data cannot be sent out, so communication is impossible.

Hope to help you!