Having Ethernet and your antenna co-located is not an ideal situation. But then most amateur antenna situations involve compromises. The general idea of the following recommendations is to take as many precautions as practical to minimize the interference possibilities.
I recommend that your Ethernet cable to your WAP be a CAT6 shielded cable (STP). While obviously not needed for your Ethernet environment, the improved twists of the CAT6 cable along with the foil shield will improve the immunity of the Ethernet cable to ingress from your antenna while transmitting as well as increase the attenuation of leakage from the Ethernet cable to your antenna while receiving.
Your Ethernet cable should also have a few toroid cores of type 43 material spaced along its length to further improve the performance of the shield. Wrap 4 to 6 turns of the cable around each toroid. This attenuates common mode currents that may be flowing along the exterior of the Ethernet shield.
Your transmission line to the antenna should be a double shielded type coax (braid plus foil). This helps to minimize ingress / egress from your transmission line.
Use a high quality, ferrite 1:1 balun at the feedpoint of the antenna. This helps to reduce common mode currents on the cable that can cause interference to your Ethernet from your transmitter or cause interference from the Ethernet to your receiver.
Ensure that your coax length is not close to an odd multiple of 1/4 wavelength (electrical length) for the bands on which you wish to operate. An ideal length is an odd multiple of 1/2 electrical wavelength as this presents the highest impedance for common mode currents. Note that this electrical wavelength relates to the outside of the shield and is influenced by the type of jacket that is on the exterior of the coax cable.
Pay attention to the layout of the cables and antenna. To the greatest extent possible, have cables cross in a perpendicular fashion instead of running or meeting in a parallel fashion. Similarly have the antenna in a perpendicular orientation to the Ethernet cable. This helps to minimize the coupling between the two systems.