Python enables the sending and receiving of multicast data

In the project, the Ys Private protocol uses multicast technology, which uses Python to send multicast packets when verifying its security features, and to make a record here.

The multicast server is used to send multicast packets to the multicast group with the following implementation code:

#coding: utf-8, import socket import Timeany='0.0.0.0'Senderport=1501mcast_addr='224.168.2.9'Mcast_port= thesock=Socket.socket (socket.af_inet, socket. SOCK_DGRAM, Socket. IPPROTO_UDP) Sock.bind ((Any,senderport)) #绑定发送端口到SENDERPORT, that is, the send port for this example is 1501sock.setsockopt (socket. IPPROTO_IP, Socket. Ip_multicast_ttl,255) #设置使用多播发送 while 1: Time.sleep (Ten) Sock.sendto ('Hello World', (Mcast_addr,mcast_port)); #将'Hello World'A specified port that is sent to a multicast address, and members belonging to this multicast group can receive this information

The packets captured by Wireshark are as follows:

The multicast client is used to receive multicast packets sent by the multicast server with the following code:

#coding: utf-8, import socket import Timeany='0.0.0.0'mcast_addr='224.168.2.9'Mcast_port= thesock=Socket.socket (socket.af_inet, socket. SOCK_DGRAM, Socket. IPPROTO_UDP) #创建UDP socketsock.setsockopt (socket). Sol_socket,socket. SO_REUSEADDR,1) #允许端口复用 Sock.bind ((any,mcast_port)) #绑定监听多播数据包的端口sock. setsockopt (socket. IPPROTO_IP, Socket. Ip_multicast_ttl,255) #告诉内核这是一个多播类型的socketstatus=sock.setsockopt (socket. Ipproto_ip, #告诉内核把自己加入指定的多播组, the group address is specified by the third parameter of the socket. Ip_add_membership, Socket.inet_aton (MCAST_ADDR)+Socket.inet_aton (any)); Sock.setblocking (0) TS=time.time () while 1:     Try: Data, addr= Sock.recvfrom (1024x768) except Socket.error, E:passElse: Print"We got data!"Print"From :", addr Print"DATA:", the data

The key to multicast client code is through (socket. Ip_add_membership) add itself to the multicast group and listen to multicast ports (MCAST_PORT) specified on the multicast server, in addition, the destination address of the multicast server must be a valid multicast address, not a unicast address, such as: (LocalHost/ Inaddr_any/any valid IP).

Python enables the sending and receiving of multicast data