Can you ping the Arduino using the public ip?
I use my Mega/Ethernet shield with a public ip.
I can't ping(WITH my Phone) the arduino when it has pulled a Public IP.
I pulled the Ethernet cord from my arduino and plugged it into my PC. It pulled a different Public IP as expected. When I use the ping functionality from my phone's app, I cannot ping the public IP of my pc either. I know the ping functionality works, because I can successfully ping Google with my phone.
Is it my ISP?