If EFT test failures are observed after trying the above steps, the issue is most likely on the DUT side. Similar to ESD testing, EFT tests can also introduce a burst of common mode noise into the system. Here are some recommendations to reduce common mode noise and mode conversion on the DUT side:

• Remove bob smith termination on unused pair
  • Having a bob smith termination on the unused pair can provide a smaller impedance path to earth ground. This results in higher common mode noise flow to the unused pair and couples the noise to the used pair
  • On the used pair, common mode impedance is generally large due to the common mode choke
    
• Solid earth ground path on the connector ground of DUT
• Solidground plane under the MDI lines for better impedance matching
• Verify ground isolation is present to reduce ground bounce in the system
• No shorted center taps on the transformer
  • Reduces cross talk
  • Reduces chance of mode conversion
• Discrete magnetic and RJ45 connector reduces the injection area of ESD noise, improving the transformer performance during ESD tests
• Optimize MDI lines layout to reduce the common mode noise picked up from surroundings, ground bounce, and other signals on the PCB.
• Optimize PCB connector ground to provide a better ground path and minimize the effect of coupling to the MDI lines