`if (ether.begin(sizeof Ethernet::buffer, mymac) == 0,PA9)` should be `if (ether.begin(sizeof Ethernet::buffer, mymac, PA9) == 0)`
if (ether.begin(sizeof Ethernet::buffer, mymac) == 0,PA9)should beif (ether.begin(sizeof Ethernet::buffer, mymac, PA9) == 0)