"Connection refused. Is the sketch using bridge?"

Hello, I'm currently attempting to setup my Arduino Mega2560 with a Dragino Yun Shield. I followed all of Dragino's documentation for setup, and successfully uploaded my sketch to the Arduino. However, whenever I access the serial monitor, it keeps failing to connect. I've also tried accessing the Console, but whenever I attempt to telnet I keep getting "telnet: can't connect to remote host ( Connection refused."

I'm aware about setting the mega16u2 into reset mode. I shorted the two pins on the icsp with some thin gauge wire, but still no change...

Does anyone have any suggestions? It would much appreciated!