multicast

问题 I have created structure : struct buffer { string ProjectName ; string ProjectID ; } buffer buf; buf.ProjectID = "212"; buf.ProjectName = "MyProj"; Now to send this structure using sendto method , I am typecasting the strucure and sending it back as below: char *sendbuf = (char*)&buf; sentbytes = sendto(sock,sendbuf,strlen(sendbuf),0,(sockaddr*)&their_addr,sizeof(their_addr)); But while I am casting my Struct ti char* the actual data is loosing it's values and while debugging I see sendbuf is

问题 i receive data from multicast for my UDP sniffer, but only in IPv4. My code looks like this, try: s = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_UDP) except socket.error as msg: print('Socket could not be created. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]) sys.exit() mreq = struct.pack("4sl", socket.inet_aton('239.255.11.3'), socket.INADDR_ANY) # receive a packet s.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq) packet = s.recvfrom(65000) But i am

问题 I have written a programm running on Ubuntu LTE that should send an Multicast-Message to 239.255.25.25 Port 5004 using a raw socket. To receive the Multicast, I am using an UDP Socket. The data to send via the socket was captured with wireshark from an rtp stream. The Problem is now, that I am not able to receive the Message with an UDP Socket. For checking if the receiver is correct, I had built an Sender, which is using an normal UDP Socket. When I am now sending the same message via RAW

问题 I have a client/server LWIP program that works correctly with unicast communication however I want to use multicast features so I used IGMP library did the following: 1- in lwipopts.h: #define LWIP_IGMP 1 //allowed IGMP 2- in ethernetif.c: netif->flags |= NETIF_FLAG_IGMP; //in low_level_init function 3-in my source file (for both client and server projects): implemented the following code: void recCallBack (void) { printf("connected"); //BREAK_POINT } static void UDP_Multicast_init(void *arg)

问题 I need to use multicast in Python application, after googling a bit I found snippets of code that works, here it is: # UDP multicast examples, Hugo Vincent, 2005-05-14. import socket import sys import struct def send(data, port=50000, addr='239.192.1.100'): """send(data[, port[, addr]]) - multicasts a UDP datagram.""" # Create the socket s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # Make the socket multicast-aware, and set TTL. s.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL,

问题 I am wondering for the udp multicast to work, router must support it? 回答1: Multicast is based on dynamically generated trees that can (theoretically) span the entire internet. These multicast trees are based on two protocols: IGMP : Internet Group Management Protocol. Used by receivers and users like me and you. PIM : Protocol Independent Multicast. Used by routers to replicate and reroute the packets accordingly. The client needs to be IGMP -compatible, and the routers need to be PIM

问题 Suppose I have no network card installed on my computer, and I would like to have functionality similar to the following: Process 1 will publish messages to some URI, say "Uri1" var publisher = new Publisher("Uri1"); publisher.publish(new Message("Somedata"); Process 2 will both listen for messages on "Uri1" and publish messages to "Uri2" var subscriber = new Subscriber("Uri1") subscriber.MessageReceived += data => Console.Writeline(data.ToString()); var publisher = new Publisher("Uri2")

问题 I have several embedded machines listening and streaming rtp audio data to a multicast group. They are connected to a smart managed switch (Netgear GS108Ev2) which does basic igmp snooping and multicast filtering on its ports, so that the rest of my (W)LAN doesn't get flooded. At start everything works fine for about 500-520 seconds. After that, they don't receive any more data until they leave and join the group again. I guess the switch is "forgetting" about the join after a timeout. Is

问题 I'm trying to send a multicast packet on all my network interfaces(2 LAN, one wifi). I initialy followed this tutorial. The problem I encounter, is that it seems that the packet seems to be with only one of my IP address. Here is my current code. private static void SendOnAllCards(int port, String address) { using (Socket mSendSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp)) { mSendSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership,

问题 I am using VirtualBox on a WINDOWS7 as host of two DEBIAN7.7 guests, deb1 and deb2 . Each guest can comunicate with the other one. Using one guest browser I can see the Wildfly istance welcome page that's running on the other guest. I run each istance in standalone-ha mode, network interfaces have mutlicast enabled, I can see on Wildfly node named srv1 that the two istances build a cluster: ... ...ISPN000094: Received new cluster view: [srv2/web|3] (2) [srv2/web, srv1/web] where srv1 and srv2