pylon:
Also provide an overview of the network connections and all involved devices (Arduino Shield, switches/hubs, router, PCs, that video device, etc.).
Did you check the cables.
Do I understand that correctly, you have several installations of the same type? Did you check that every MAC address in your network is unique?
yes i checked the cable i didn't check every mac i changed the mac of three arduinos so two of them the changes give results but the last one doesn't change
SurferTim:
What is atem? A link may be helpful. Maybe it is using all the available sockets at times. No available socket, no ping response.
atem is video switcher and i need to control it so it can be controlled with atem no some of ethernet shields are working probably but some drop packets
i changed the mac of three arduinos so two of them the changes give results but the last one doesn't change
Describe in more detail what that means. You did change the MAC address from what value to what value? The change of the other two Arduinos gave what result? Did it fix the problems?