Use the proper cabling for your network topology as specified by IEEE. Make sure cable segments do not exceed the recommended lengths.

Make sure cable segments are properly terminated for the type of cabling being used.

Make sure terminators and in-line cable connectors are working properly.

If you are not sure whether a terminator or connector is working properly, replace it. If the new components work properly, discard the old ones.

Make sure there are no breaks in the cable or shield. Use a time delay reflectometer (TDR), a LANalyzer, or a volt ohm meter (VOM) to test cabling for breaks in the cable conductor or shield.

Make sure cabling is routed away from devices that produce high electric or magnetic fields, such as fluorescent lights, microwaves, radar, X-rays, copy machines, etc.