Just ran the command
system("ifconfig > /dev/ttyGS0");
And it seems that eth0 is not even found. I wonder why? I am positive it did show up at some point before. (Before the firmware update, at least).
OK, the issue solved!
For some reason I have to put the interface up and down when the board is rebooted.
So I just put the following in my program:
In case anyone else gets in the same trouble