Bernard's

密码 从明文存储，到两次md5加盐加密，再到bcrypt 前后交互 文件：二进制传输 参数json 先传文件再传参？ 文件上传 先传本地再传HDFS？ 很不安全 串联，把本地文件系统的问题带到 如果要做真的分布式，会把问题变得更复杂 直接流式写入 跨域方案 无限制跨域 @crossorigin axios 在传输表单的时候会带*，冲突 限制前端IP和端口 ...

1 What is the IP address of your host? What is the IP address of the destination host? 我的主机IP地址是内网地址，而目的IP是公网地址 2 Why is it that an ICMP packet does not have source and destination port numbers? ICMP包没有源端口号和目的端口号，因为它设计的目的是在主机和路由器之间交换网络层的信息，而不是在应用层进程之间

1 Are DHCP messages sent over UDP or TCP? 2 Draw a timing datagram illustrating the sequence of the first four-packet Discover/Offer/Request/ACK DHCP exchange between the client and server. For each packet, indicated the source and destination port num