multicast

问题 I have a device on the network that is multicasting a very small file via UDP. The iOS app I am developing is responsible for reading these packets and I have chosen to use GCDAsyncUdpSocket to do so. The file is sent every half second, however I am not receiving it nearly that often (only receiving about every 3-10 seconds). Thinking that it may be an issue with the device, I began monitoring the traffic with Wireshark. This appeared to reflect what I was seeing in my app until I enabled

问题 I need to determine the IP of a machine that has sent me a multicast packet, so that I can respond to it via unicast. I'm using the following csharp (.Net 3.5) code to receive the packets over a multicast connection (code has been edited for brevity, with error checking and irrelevant options removed): IPEndPoint LocalHostIPEnd = new IPEndPoint(IPAddress.Any, 8623); Socket UDPSocket = new Socket(AddressFamily.InterNetwork,SocketType.Dgram,ProtocolType.Udp); UDPSocket.SetSocketOption

问题 I am trying to connect to a multicast group using the following piece of code: int flag_on = 1; /* socket option flag */ struct sockaddr_in mc_addr; /* socket address structure */ char recv_str[MAX_LEN+1]; /* buffer to receive string */ int recv_len; /* length of string received */ char* mc_addr_str; /* multicast IP address */ unsigned short mc_port; /* multicast port */ struct sockaddr_in from_addr; /* packet source */ unsigned int from_len; /* source addr length */ mc_addr_str = ip; /* arg

问题 How do you send and receive UDP multicast in Python? Is there a standard library to do so? 回答1: This works for me: Receive import socket import struct MCAST_GRP = '224.1.1.1' MCAST_PORT = 5007 IS_ALL_GROUPS = True sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) if IS_ALL_GROUPS: # on this port, receives ALL multicast groups sock.bind(('', MCAST_PORT)) else: # on this port, listen ONLY to MCAST_GRP sock.bind

问题 I am following Boost's UDP Time server tutorial here . I modify the code with these for predefined values: short multicast_port = 13; // (in class receiver) and in main(): //if (argc != 3) and the code for argv that follows are commented out receiver r(io_context, boost::asio::ip::make_address("127.0.0.1"), boost::asio::ip::make_address("127.0.0.1")); // This error is thrown: set_option: The requested address is not valid in its context I have tried "0.0.0.0" and "127.0.0.1" and other values.

问题 All my processes have two sockets, one PUB and one SUB, and they all use the same multicast address and port. For example, PUB will do this: bind("epgm://239.192.1.1:5555") SUB will do this: connect("epgm://239.192.1.1:5555") setsockopt(ZMQ_SUBSCRIBE, "", 0); //subscribe everything PUB will then send message by calling zmq_send, and SUB will receive by calling zmq_poll and do Nonblocking zmq_recv. It works perfectly fine when I run two processes on two different hosts. But if I run them on

问题 For my project, I need some way to know which multicast group a packet was originally sent to when it's received by my client. I've considered maintaining a map of sockets to multicast groups and identifying them this way, but surely there's some way to get the address from the datagram? To listen, I'm currently using: # Initialise socket for IPv6 datagrams sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP) # Allows address to be reused sock.setsockopt(socket.SOL

问题 I have 2 java threads receiving UDP multicast. Each thread will receive UDP packets from different multicast streams of say around 60 Mbps, then processes UDP packets and queues in shared BlockingQueue . UDP packets are of around 1300 bytes. I want order of processed UDP packets in queue, which is same as how packets reached to NIC of machine, even if receiving packets from different threads(different multicast streams). I am not able to achieve this in these threads, that is my problem. Is

问题 I need to send two different XMLs (by FreeMarker) to two different endpoints. i.e. .to("freemarker:templates/xml1.ftl").to("file://C:\\testXmls1") and .to("freemarker:templates/xml2.ftl").to("file://C:\\testXmls2") I had a look at the multicast() function but I don't know how to apply it when there are two .to Could anyone please help me? 回答1: Yes you can specify multiple endpoints in the same .to(uri1, uri2, ...) then it becomes as a single "eip". multicast() .to(uri1a, uri1b) .to(uri2a,

问题 I want to capture network traffic on specific Multicast IP address and port number. For testing purpose, I replay pcap file over a network on 225.1.1.7 ip and 3100 port. I tried to capture using tcpdump using below command - sudo tcpdump -i eno1 -s0 -vv host 225.1.1.7 and port 3100 and it is working file. I have below java program - class Temp { public static void main(String[] args) throws UnknownHostException, IOException { int port = 3100; String group = "225.1.1.7"; MulticastSocket s =