Ethernet2 (UDP) SPI transfers have a lot of dead time

sketch_nov25a: In function 'void loop()':
sketch_nov25a:7: error: 'current_micros' was not declared in this scope
current_micros = micros();
^
sketch_nov25a:8: error: 'Testpin' was not declared in this scope
digitalWrite(Testpin, HIGH);
^
sketch_nov25a:9: error: 'Udp' was not declared in this scope
Udp.beginPacket(Remote_IP, Remote_Port);
^
sketch_nov25a:9: error: 'Remote_IP' was not declared in this scope
Udp.beginPacket(Remote_IP, Remote_Port);
^
sketch_nov25a:9: error: 'Remote_Port' was not declared in this scope
Udp.beginPacket(Remote_IP, Remote_Port);
^
'current_micros' was not declared in this scope