NodeJS UDP Multicast How to
Changed: client.addMembership(‘230.185.192.108’); to client.addMembership(‘230.185.192.108’,HOST); //Local IP Address
multicast
How can I use TCPDump on Unix to view messages sent to a specific multicast address?
I believe this should be enough for a specific group: tcpdump -i eth0 -s0 -vv host 239.255.255.250 All multicast traffic: tcpdump -i eth0 -s0 -vv net 224.0.0.0/4
how to list rooms on socket.io nodejs server
The short answer: io.sockets.adapter.rooms I analysed io: I got the following output: { server: { stack: [ [Object], [Object], [Object], [Object], [Object], [Object] ], connections: 3, allowHalfOpen: true, watcher: { host: [Circular], callback: [Function] }, _events: { request: [Function], connection: [Function: connectionListener], listening: [Object], upgrade: [Object] }, httpAllowHalfOpen: false, cache: {}, settings: { home: “https://stackoverflow.com/”, … Read more
Getting `Can’t assign requested address` java.net.SocketException using Ehcache multicast
This was caused by an IPv6 address being returned from java.net.NetworkInterface.getDefault(). I’m on a Macbook and was using wireless — p2p0 (used for AirDrop) was returned as the default network interface but my p2p0 only has an IPv6 ether entry (found by running ipconfig). Two solutions, both of which worked for me (I prefer the … Read more
Can I use broadcast or multicast for TCP?
No, you can’t. TCP is a protocol for communication between exactly two endpoints. Compared to UDP it features reliable transport, that means, that packets get not only send, but it is expected that the peer acknowledges the receipt of the data and that data will be retransmitted if the acknowledgment is missing. And because Broadcast … Read more
How do I choose a multicast address for my application’s use?
It seems you’ve already found http://www.iana.org/assignments/multicast-addresses, so you’ve done the right thing by picking an address from the 239.255/16 range. As those ranges are entirely for site-local use it’s no ones else’s business which particular address you pick, but you may need to coordinate with the network manager (assuming that’s not you) to pick an … Read more
What does it mean to bind a multicast (UDP) socket?
To bind a UDP socket when receiving multicast means to specify an address and port from which to receive data (NOT a local interface, as is the case for TCP acceptor bind). The address specified in this case has a filtering role, i.e. the socket will only receive datagrams sent to that multicast address & … Read more
How do you UDP multicast in Python?
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((MCAST_GRP, MCAST_PORT)) mreq = struct.pack(“4sl”, socket.inet_aton(MCAST_GRP), socket.INADDR_ANY) sock.setsockopt(socket.IPPROTO_IP, … Read more