1. Check whether the network card speed and working mode are specified (change to auto-negotiation or a speed mode that both ends can support);

2. Whether the rate of the peer device matches the network card. The electrical port network card defaults to auto-negotiation mode and will adapt to the lowest rate at both ends;

3. Check whether the twisted pair cables comply with regulations, whether they are correctly wired, and check the cable quality (for example, 10G uses network cables of Category 6e or above or above, etc.);

4. If it is a multi-port network card, set the speed and working mode of two network ports to auto-negotiation, and use a confirmed cable to directly connect the two network cards to see if the speed is normal.