I have searched the web for this with no success.
This is my problem:
I am developing app that reads data from arduino connected with Ethernet shield.
I can connect to it on the internal network (home network) or trough the internet.
The problem is I need to know if the arduino is present on the local network and if not then look for it on the external ip address.
I have tried to use the ping function but it’s not working.
Any help would be appreciated.