udp
client，接收服务端转发的地址，直接发送即可，路由器上在连通的情况下会自动记录内外端口号，并在短时间内关闭，所以需要循环发送数据
代码语言：javascript复制def main(host='127.0.0.1', port=9999):
sock = socket.socket(socket.AF_INET, # Internet
socket.SOCK_DGRAM) # UDP
a = 0
while True:
try:
print("------------send {}".format(a))
sock.sendto(b'0', (host, port))
a =1
break
except Exception as e:
time.sleep(3)
continue
while True:
data, addr = sock.recvfrom(1024)
print('client received: {} {}'.format(addr, data))
addr = msg_to_addr(data)
sock.sendto(b'0', addr)
data, addr = sock.recvfrom(1024)
print('client received: {} {}'.format(addr, data))
if __name__ == '__main__':
logging.basicConfig(level=logging.I
