1. Check whether the network port is disabled. (For Windows, you can check the Device Manager or "Control Panel\Network and Internet\Network Connections"; for Linux systems, you can use the IP -a command to check whether the status of the network card is up.)
2. Check whether the connection of the network cable is defective (replace with a new network cable for verification test);
3. Whether the equipment at the other end is defective (including system, network port, etc.);
4. Check whether the connection rates at both ends match (generally the default is adaptive);
5. Replace the network card and check whether the individual network card is defective.
1. It is necessary to verify that the speed of the optical fiber equipment at both ends is consistent (use the same brand and model of optical fiber modules);
2. It is necessary to verify that the speed of the optical fiber modules at both ends matches the speed of the equipment at both ends (use the same brand and model of optical fiber modules);
3. The optical fiber modules at both ends have the same wavelength and the same speed (use the same brand and model of optical fiber modules);
4. The optical fiber modules used do not match (usually occurs on single-mode single-fiber connection links. The optical fiber modules at both ends use the same model, causing the connection to fail. The parameters of one end are: TX 1550nm RX 1310nm, and the parameters of the opposite end need to be :TX 1310nm RX 1550nm);
5. The sequence of the optical fiber jumper must be correct (generally the connection method for SFP dual-fiber is: A's sending to B's receiving, A's receiving to B's sending);
6. The optical fiber module is compatible with optical fiber equipment (it involves the compatibility of various manufacturers. The best method at present is to inquire and confirm whether it is compatible before purchasing);
7. Check whether the optical module or cable is defective through cross testing (such as moving the normally used optical fiber cable to the doubtful board to confirm).
1. Need to verify that the speed of the fiber optic equipment on both ends is consistent (using fiber optic modules of the same brand and model);
2. Need to verify that the speed of the fiber optic modules at both ends matches the speed of the equipment at both ends (using fiber optic modules of the same brand and model);
3. The wavelength and speed of the fiber optic modules at both ends are the same (using fiber optic modules of the same brand and model);
4. The fiber modules used do not match (usually appearing on the connection link of single-mode single fiber, where the fiber modules at both ends use the same model to prevent connection, with one end having parameters of TX 1550nm RX 1310nm and the other end having parameters of TX 1310nm RX 1550nm);
5. The fiber optic jumper wire sequence needs to be correct (the general connection method for SFP dual fiber is: A sends to B receives, A receives to B sends);
6. Fiber optic modules are compatible with fiber optic equipment (which involves compatibility with various manufacturers. Currently, a better method is to consult and confirm compatibility before purchasing);
7. Conduct cross testing to identify any defects in the optical module or cable (such as moving the normally used fiber optic cable to a suspicious board to confirm).
