why wont my etherten microcontroller show up

When I plug my etherten controller with the Wiznet ethernet port, it wont show up on the DHCP client list. When I plug in the ethernet cord, it turns on the green light, but the yellow light only comes on once every 20 seconds or so.

Please let me know your environment, firmware, etc. Also, let me know what you mean by yellow light. Your description is so short that I can’t guess the cause.

Im in mexico with 1.4 mbps. I am using a TP Link router wr840n is the model. We are using a raspberry pi to be the server and an Etherten by freetronics for our microcontrollers. The yellow light on the ethernet port on the ·Etherten stays on and every 15 seconds, the green light blinks for a second. I think the firmware is raspberian. Does this help?

Etherten uses W5100, not W5500. is it right?
I am not familiar with Etherten because it is a third-party product.
So I’m sorry I can’t help you much

First update the Etherent2 library to the latest version in arduino, then upload the ChatServer Example.
Also check the network status by sending a ping to the static ip set in arduino.
If ping works, there is no problem with the network.
You said you don’t see the W5100 in the DHCP Client list. What did you use the DHCP code for?