Dhcp failed!

Hi guys, I have problems with my project, I have Arduino mega with W5100 ethernet shield, with this control six lights and the temperature in my bedroom, from 1 year the project works very well without problems, but since Saturday no work, in the serial monitor there is this code: DHCP failed . Arduino is connected to the secondary router that acts as a brige. If I connect Arduino in the primary router it works, in the second it doesn’t! The router works, all the peripherals connected to it work. When in doubt I purchased another router, but where is the problem? Is there any setting to be set? Second question: when there is no internet how can I switch the light on / off? In the drawing there is the connection with the physical keys with the internet works, but when it goes well it doesn’t work perfectly
Thank you for your support.
Best regards!

Your DHCP message obviously relates to an internal networking issue. My guess would be that:

  1. You are using a limited range of IP addresses that are being handed-out by your secondary router (acting as a DHCP server), and that ther devices are connected to this router and have therefore used-up all of the available IP addresses
  2. You’ve added another Arduino device and have assigned the same MAC address to that device.

I’m not sure which “drawing” you’re referring to (maybe that has translated badly and should have been ‘sketch’, as in the code that you’re running?), but you need to avoid using Blynk.begin if you want your hardware to work offline. You need to use Blynk.config and Blynk.connect instead.