Does the orientation of the magnetics with respect to the PHY matter? Meaning, should the common mode choke inside the magnetics be close to the ethernet connector or the ethernet PHY?
Can someone tell the reason what might happen if the magnetics is swapped 180deg?
Does it affect any ESD tests? Because I have one contact discharged test failed at 3kV? Can it be because of the transformer orientation swapping?
Common mode choke is intended to be used at ethernet side. I would primarily expect effects on signal quality, possibly also radiated EMI, if center tap is connected at least at one side. I won't particularly expect an effect on ESD behaviour, question is if ethernet shield is connected correctly. Otherwise you might have a problem for both orientations. Which ESD effects do you see, unspecified like uC reset, or ethernet specific?