Hi, sorry for the delay, I had just read your post and I could said "me too" But I solved the problem and it works for two years now. I explain my solution here, if the French don't afraid you. https://easydomoticz.com/forum/viewtopic.php?f=20&t=6497 I resume, a 7.5volts power supply, a passive injector, and a spécial home-made cable to bypass the RJ45 socket. The 7.5 v go to Vin-Gnd of the Nano to produce 5v wich is returned to the W5100. QED. Rpx.