Questions tagged [multicast]

In computer networking, multicast is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from the source. Copies are automatically created in other network elements, such as routers, but only when the topology of the network requires it.

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Ubuntu transmits TTL 0 multicast packets

IP packets with TTL 0 shall not leave host. But when I start application which multicasts UDP packets with TTL 0, I see packets with TTL 0 leaving host for few seconds, and coming to normal behavior ...
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I want to enable Multicast from one subnet to another

I have emulated a virtual private network : VM1 192.168.2.22 /24 VM2 192.168.3.33 /24 VM3(Router Equivalent) 192.168.2.2/192.168.3.3 VM1 and VM2 connected by the router VM3 I want to enable Multicast ...
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Iptables SNAT not applied in Multicast routed traffic

I'm trying to setup Source Nat Translation (SNAT) over routed multicast traffic with Iptables and Smcrouted. The fact is that SNAT does not apply in this cases: When traffic is routed for first time....
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Add/Remove altnet directives to pimd at runtime?

Our network supports many multicast streams using pimd. Many (but not all) of those multicast streams only flow if we use the "altnet multicast_source_ip masklen 24" statement in the phyint section ...
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Nat a multicast address between two NICS of a linux box both on different subnets

I am using Linux centOS as a router to NAT traffic between two subnets. I can route/nat unicast packets with no problem using iptables. For simplicity sake lets say I have computer A (192.168.0.1) ...
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multicast on windows 10

I have implemented an app in Android which communicates with another Windows app using multicast. It is working properly on most Windows 10 machines, but on some others the app won't receive ...
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998 views

Cannot Create QEMU Socket Networking in Windows Host using Multicast Fails with Unknown Error

I am trying to create a simulated VLAN using socket networking, and the only way to connect multiple VMs in one network in QEMU using socket networking is by using the multicast mcast option of the ...
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Why don't GCP, AWS or Azure support IGMP multicast/broadcast? [closed]

It's well known that GCP/AWS/Azure do not support IGMP multicast or broadcast. Some state it's because of security concerns, but don't mention what those concerns are. Is there a reason why these ...
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Windows DHCP MADCAP Server Multicast Addresses

I am very familiarized with DHCP server role on Windows OS, but I have a doubt regarding multicast scope. From what I understand, a multicast scope will assign MADCAP clients with a multicast address ...
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Use interface IP address for response to incoming multicast packet

I have a multicast routing setup with forwarding on the receiving side, as follows (all Linux): +----------------+ +----------------+ +-------------+ | openvpn-server |...
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Set up multicast route across a middle hop

I have a host with two Docker containers (with NET_ADMIN capability): backend with an interface eth0 (172.16.7.3) openvpn-server with interfaces eth0 (172.16.7.2) and tun0 (10.8.0.1), running an ...
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How can I make my libvirt/KVM guest see all IPv4/UDP multicast traffic?

I have an issue with IPv4/UDP multicast traffic not being fully visible from within a KVM guest. The guest has a dedicated NIC which is attached using MacVTap. Both the host OS and the OS in the ...
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Windows 10 becoming un-responsive when receiving lots of UDP multi-cast network traffic (but not with unicast traffic)

By coincidence we found that our Windows 10 machines (running version 1607 or 1809) becomes sluggish and/or start stalling when we throw lots of UDP multicast traffic on them. This happens if we send ...
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manycast servers aren't used (receive: AM_MANYCAST drop: bad auth || (NOPEER|NOTRUST))

I created an NTP configuration for SLES12 SP4 (ntp-4.2.8p13) where only selective interface addresses are being used, and I tried to discover statum-1 and startum-2 servers via manycast (ACST) in our ...
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nuttcp multicast testing of server/switch combination under Ubuntu (18.04)

I am trying to test a server/switch combination on a system with 10Gb interfaces. I want to have the server generate multicast messages using nuttcp, and two or three client devices receiving the ...
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How can I see multicast traffic from the same host?

On Fedora 30, I'm trying to see multicast packets in another process on the same host. Using netstat, iperf, and tcpdump, I've verified that the group is joined and packets are sent to the multicast ...
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Why my Multicast is not working between two PCs?

I am working with multicast and streaming a file using 224.0.0.149 IP. With my PC I can listen to the stream using VLC client. But when I try to receive from different PC with the same router I couldn'...
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Is there such thing as a multicast LOOPBACK IP address, which won't leak packets from my host?

I need to work with and test a multicast application on my machine. If I configure its multicast IP to be something like 224.0.0.0, it will interfere with my other co-workers who are also working with ...
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Trouble with IGMP messages only coming out on a single interface

Situation: The Linux box has two interfaces (eth0 and wlan0). For both there is a default route but eth0 is preferred because of metric settings. Goal: I want to receive multicast traffic for a ...
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How can I forward port from two multicast addreses with the same port using iptables on debian?

I wrote a multithread program in Python, that analyses traffic from two multicast addresses with the same port, however it looks like my threads don't distinguish from where are datagram's coming. ...
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MDNS response “storm” with “localhost_prl: 127.0.0.1”

We are experiencing occasional performance problems in our WIFI. With Wireshark I see a high number (currently 50/s) of MDNS responses for localhost_prl:127.0.0.1. I don't think that this is normal. ...
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Can a linux client in a multicast network get to know the source ip?

Supose I'm added as a client in a small multicast network with L2 switches and one unique router that is the LHR that uses IGMPv2. Can I (legally if possible) forward some signal that will give me the ...
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“Operation not supported” error when using sendto api with multicast on FreeBSD socket

I have got some weird issues. I want to send data by using multicast address on the FreeBSD socket. Here is the sample code. // bind socket bind(sd, (const struct sockaddr *) &saddr, sizeof(...
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Multicast not reaching application layer - Windows 10

I have a python application that receives multicast packets from one of the ethernet ports set to a static ip on a windows machine. The other ethernet port is a usb-eth dongle configured for another ...
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“Cannot set device ring parameters: Operation not supported”

I'm trying to change the RX and TX for an HP BL460C server by using ethtool and get the following: ethtool -G eth0 rx 4078 tx 4078 Cannot set device ring parameters: Operation not supported My ...
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312 views

multicast routing between vlan

I am trying to create a multicast messaging service between vlans. When both multicast client and server are in same vlan, the client receives the packet without any issues. When client and server in ...
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510 views

multicast traffic across vlan

Suppose I have a layer 2 managed switch which can be programmed to have multiple VLANs. Lets say there are 2 configured VLANs as of now vlan-1 and vlan-2. I also have a linux machine with 2 ethernet ...
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Multicast for Tomcat servers on Google Cloud

Google Cloud VPC networks only support IPv4 unicast traffic [1], they do not support broadcast, multicast or IPv6 traffic within the network. I have several tomcat servers and I'd like to group them ...
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Multicast communication betwen two subnets connected to one switch

Computers A and and B are connected to the same switch. A is in subnet 192.168.1.0/24, B in 192.168.2.0/24, so they cannot communicate directly using unicast. But what about multicast communication? ...
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Change network interface for multicast subscription

My laptop has 2 network interfaces: ethernet (eno1, 600 Metric) and wireless (wlo1, 1000 Metric) Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface ...
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cisco 4948 IGMP flooding on all ports

everyone Having trouble with multicast on cisco WS-C4948-10GE (MPC8540). I have two switches running: System image file is "bootflash:cat4000-i5k91s-mz.122-25.EWA9.bin" and System image file is "...
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running snort and IGMP v2 flooding

I am not a network guru so please bear with me. I am running snort on a PLC (running rt-linux) along with an application that needs to communicate with another instance of the same application ...
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Is it possible to configure an IPv6 multicast address to a NIC?

Is it possible to configure an address from ff00::/8 address block to a NIC? Looks like it is not possible: # ip a add ff99::1/8 dev p2p1 RTNETLINK answers: Cannot assign requested address # # ip ...
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routing multicast trough debian miniPC eth0->eth1

Hello i have probably noob question by i already spent some time on it and messed a local network as well so: I have miniPC for real time log purposes between network and IPTV set-top box. The box ...
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Redhat No IGMP response

I'm setting up my server to ingest a multicast. The server will initiate the request and can join the multicast for about 2:30-3:30 min. After that, it gets dropped from the multicast group due to no ...
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423 views

iptables translate multicast to unicast

I'm attempting to translate multicast traffic to unicast to send over the Internet. I enabled ip forwarding and tried using the following rule: iptables -t nat -A PREROUTING -i eth0 -d 239.0.0.0 -j ...
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WDS stopped working - no servers under Windows Deployment Services 2008 R2

I have three Windows 2008 R2 servers with MDT and WDS installed. It was reported multicasting stopped working on all of them. I made sure the multicast option was selected in the deployment shares' ...
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Forwarding traffic - passive behavior

I spent some time trying to figuring this out. I found my core solution, but iam not satisfied, or more likely i dont fully understand the result, which buggs me. My setting: I have wall plug(port) ...
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Receive multicast frames from different subnets

I'm trying to receive on my LInux box multicast frames from hosts on a different subnet. For the experiment, and ONLY for this experiment, i have two machines connected through a network switch: ...
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1answer
281 views

Is IPv6 MLD snooping performed by Layer2 Switches over solicited-node multicast addresses?

The NDP protocol makes use of the solicited-node multicast address. A host joins its own solicited-node multicast address group both localy (netsh int ipv6 show joins) and on the layer2 domain (a ...
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882 views

Java Multicast Socket doesn't receive anything on Windows

I need to send and receive in multicast. I posted the question on StackOverflow Forum for checking my code: https://stackoverflow.com/questions/50131973/java-multicast-socket-doesnt-receive-anything-...
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Named multicast address

Is it possible to name a multicast or broadcast address? Usually for a single machine I'd put a line in /etc/hosts. Will that work for a multicast address?
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SSH TAP tunnel & multicast groups

Is it possible to do UDP multicasting over an SSH TAP tunnel? I have set up a TAP tunnel using SSH between my Ubuntu PC and a Raspberry Pi sitting in a remote office, using this command: $ ssh -o ...
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Is my NTP configuration working (with a multicast peer)?

Introduction I'm trying to do some work in which I must receive an NTP update from peers but I'm concerned that there isn't any being received. Here's the output of ntpq -np: remote ...
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Windows 10 Falls Back to IGMPv2

I have a setup where I have a Linux server running an 802.11n WPA2 encrypted Wi-Fi network. There are two devices connected to this network. One is a device which generates reports and the other is a ...
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Do all ethernet switches support multicast?

I'm playing with LANs here at home and I want to support multicast. Do all switches nowadays support multicast? Even the cheap ones? I'm buying a 5-port gigabit switch. Will it support multicast?
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What routing/topology protocol(s) should be used with P2P devices with sporadic, changing connectivity?

I have several IoT devices that will sporadically come into and out of range, and connect in a partial mesh topology. For illustration purposes, imagine the interconnectivity of a Web of Trust, or ...
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What does having a network that would allow a multicast address to find host computers mean?

I'm dealing with a scenario with a service that's saying the following: "... [this service] uses multicast address 239.170.165.207 on port 49838 to find host computers, so your network must allow ...
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212 views

Arista switch - Forward multicast traffic from vlan to vlan on different switch ports with different subsets

I have an Arista DCS-7150S-24-R I got a cross connect from provider X into port #1 (port marked as vlan 100) I got a linux host connected to to the switch at port #2 (port marked as vlan 200) Ports ...
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769 views

How can I tunnel multicast traffic?

I am trying to receive multicast on 1 machine, forward it to another machine, and then replay it on that machine. test_env: the machine which has access to the original multicast stream mcast_sender: ...

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