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.
296 questions
0 votes
0 answers
136 views
Multicast video stream from Dahua IP surveillance camera - ffmpeg etc
I have a Dahua IP surveillance camera and want to get the video via a multicast stream. In the camera settings, I enabled Multicast streaming, IP 239.240.1.2, and port 40000 (the default). The RTSP ...
1 vote
0 answers
62 views
iptables NAT-ing multiple clients requesting service to a multicast address; server replies with unicast packets; How to route back to client?
We have an E device that sends a request multicast (239.1.2.3) UDP to port 17225 in network netE. The replier listens to the multicast address request, and replies with unicast UDP to the requester. ...
1 vote
0 answers
83 views
ICMP echo reply to a multicast ping not properly de-NATing because the src ip on the reply is set to the multicast address
So I have 3 linux machines like so: Machine 1 Machine 2 Machine 3 ----------------------- ------------------------ ----------------------- | ...
- 11
0 votes
0 answers
94 views
Difference between multicast forwarding cache and multicast routes
I'm trying to understand multicast routing on Linux and have some questions regarding to it: what is the difference between route of type multicast that is usually displayed using ip route command ...
- 141
1 vote
1 answer
202 views
What IP to assign my NIC in order to receive multicast traffic
I have a device (Blackmagic 2110 IP Converter 3x3G) connected to my PC that is sending me some ST-2110 video stream over 239.255.2.164. I need to receive this data. My NIC does not have any IP address ...
- 113
1 vote
0 answers
344 views
How to configure Kubernetes Clusters for sending and receiving UDP Multicast
I am trying to configure Kubernetes pods to send and receive UDP Multicast messages. I have two clusters, each is running on a separate Proxmox VM. Each cluster is using Flannel as the base CNI with ...
- 11
1 vote
1 answer
296 views
Make libvirt guest able to receive multicast traffic from the host network
I have a network defined by libvirt, The problem From the guest I cannot query the devices that are connected to the LAN, nor does the guest see multi-cast traffic which the host is able to see. The ...
- 111
0 votes
1 answer
727 views
Which ip is chosen as source ip when sending a multicast packet on a specific interface with multiple ip addresses?
I am trying to send a multicast packet on a network interface with multiple host ip addresses(lets say ips A and B). How can I specify the source ip field of said multicast packet to the host ip that ...
0 votes
1 answer
565 views
How do I configure multicast to be used with rsync in batch mode
The rsync man page says "Multicast transport protocols can be used to transfer the batch update files in parallel to many hosts at once, instead of sending the same data to every host ...
- 97
0 votes
1 answer
1k views
Casting videos from one PC to multiple displays over an Ethernet Network
have a set of 6 television displays spread over 3 floors and a central personal computer at one of these floors. There exists an Ethernet cat6 cable network in the building with ports at the location ...
- 11
1 vote
0 answers
705 views
Linux bridge does not propagate multicast ntp messages
My hardware, based on imx8, has two ethernet interfaces. These are connected together as a bridge, all messages not for this he are forwarded. Everything works as expected except multicast messages: ...
- 11
0 votes
1 answer
5k views
Use container hostname resolution with network=host
I have two docker container. One is the "backend", the other "connector".. The connector needs to have its network type set to "host" (To receive udp multicast: ssdp/mdns ...
- 137
0 votes
1 answer
74 views
What are the downsides of using IPv6 Multicast for majority of all communication including one-to-one?
Given IPv6 Multicast allows for a sub-pub communication model, it seems like a no-brainer for the vast majority of communication, but its very rarely used beyond video streaming, and I'd like to know ...
1 vote
1 answer
822 views
Is there a way to add multicast to loopback interface on a kubernetes pod?
Using an in-prem kubernetes installation on baremetal (Ubuntu) servers, installed with kubeadm. Kubernetes version is 1.25.3 Need to have multicast on a pod's loopback for the automated tests running, ...
- 123
2 votes
1 answer
4k views
Multicast between kubernetes pods
I have an app in which there are a few tasks that communicate using publisher/subscriber. The main problem is that the pub/sub discovery works by multicasting information to the other tasks, but when ...
- 31
0 votes
1 answer
247 views
Dynamic multicast in AWS not working using IGMPv2
I have a java application running on tomcat on multiple ec2 instances, and I want to deploy it in cluster mode which is working when I configure in each tomcat server a StaticMembershipInterceptor for ...
- 101
0 votes
0 answers
615 views
Multicast resolution overrides hosts file on Windows 10
I have a Windows application that publishes itself with a DNS multicast record. Let's say myapp.local. When it is installed, it stores a record in hosts file under systemroot/drivers/etc folder. 127.0....
- 1,488
1 vote
1 answer
822 views
How do multicast addresses on the public internet resolve
A service we use is asking us to whitelist the IP 255.0.0.1 in order for us to use them. I understand this is a limit broadcast address and falls under the category of multicast addresses. How do I ...
- 41
0 votes
2 answers
2k views
Multicast packets never received by socat
I have three machines running Manjaro, two work just fine, but the third (a Raspberry Pi) seems to not pass multicast packets to the registering application. This is similar to this question. On the ...
- 319
0 votes
0 answers
379 views
CARP getting confused with 2 interconnected switches and bonding
I'm having a pretty straight forward 10G switch setup: +-----+----+ +-----+----+ | |port2 ISL port2| | | switch A +--------------------------+ ...
- 1
0 votes
0 answers
470 views
I want to test IGMP capability of a OpenWRT based router. How caan i test?
This is what I want to test out, SEE IMAGE: Router connected to users and is accessible over the internet as well PC1 and PC2 should be able to join some group(s). Should be able to leave group as ...
0 votes
1 answer
459 views
802.1q multicast blocked by Cisco router
We are using Cisco Catalyst 1000 switch (C100-16P-2G-L to be precise) and having a trouble of passing tagged multicast from one its port to another. We would like to pass it as it is (tagged), I ...
- 155
0 votes
1 answer
2k views
Does Windows automatically leave unused multicast groups?
When troubleshooting multicast, I found no reference on the meaning of the fields returned by this command: C:\Users\Administrator>netsh int ip show joins level=verbose Interface 5: Ethernet0 ...
- 158
0 votes
0 answers
77 views
up directive not working when dhcp is selected in /etc/network/interfaces.d/eth0
I have to add the multicast route, that is needed when no default gateway is configured. Mono needs this in order to join multicast groups. The configuring is done in /etc/network/interfaces.d/eth0 ...
- 141
0 votes
1 answer
1k views
IGMP v3 JOIN sent but no traffic from switch
I'm trying to join an IGMP multicast stream from a Centos 8 machine but after sending a JOIN, there is no traffic coming from the switch. Simple connection: MUX <-----------> cisco3850 <------...
- 255
0 votes
0 answers
48 views
route packets from specific hosts to virtual device
PIMv2 I think the issue is with multicast. I want to create a GRE tunnel that supports multicast PIMv2. I am seeing the server sending PIMv2 Hello messages to my gre tunnel but my machine is not ...
- 1
0 votes
1 answer
1k views
How to configure bird OSPF for ipip link?
I have a simple ipip tunnel between 192.168.56.254/31 and 192.168.56.255/31. My simple test config on 192.168.56.254/31 looks like: protocol ospf test { import none; export none; ...
- 704
0 votes
1 answer
602 views
Cannot receive multicast frames
I'm bringing up a new machine and it cannot receive multicast frames for some reason. Everything else about the network seems to work fine. Even multicast frame seems to get out fine because I can ...
- 101
1 vote
1 answer
171 views
WCF Discovery on Windows Server 2019 getting ICMP Typ 3 Code 3
The problem: I've installed Windows Server 2019 and I am trying to discover my WCF services running on a Windows Server 2012R2. But that's not working and in Wireshark I see a ICMP Destination ...
- 111
0 votes
1 answer
5k views
Which VLANs need IGMP snooping?
My approximate understanding is that switches and similar L2 devices employ IGMP snooping to prevent multicast "streams" from propagating out of ports that have no multicast clients ...
- 357
0 votes
0 answers
840 views
Forward multicast and broadcast packets over subnets
I am trying to receive packets from the local network, including specifically broadcast and multicast on device B, which is connected to the local network though device A which is acting as a router ...
- 1
1 vote
1 answer
405 views
Using multicast DNS to broadcast name of my machine like raspberrpi does
Raspberry pi has a feature where when it's connected to a LAN, you can find its IP using raspberrypi.local (source). It mentions multicast DNS. I'd like to do this for my own linux devices on LAN, ...
- 212
2 votes
1 answer
809 views
How to make reverse mDNS through IPv6 on OSX?
I am looking for a way to make reverse mDNS query on OSX over IPv6 only. I am not interested by solution using IPv4. The following works on Linux with dig 9.16.1: dig +short @ff02::fb -p 5353 -x 2001:...
- 196
9 votes
3 answers
14k views
Why 224.0.0.1 traffic is filtered by Linux hosts?
When sending an ICMPv4 echo request to a destination address like 224.0.0.1, it is ignored by Linux hosts receiving the request. The destination MAC address used is 01:00:5e:00:00:01. The only way to ...
- 196
1 vote
1 answer
2k views
Multicast not working on macvtap device
I have a problem with my virtual network and IPv6 network discovery (multicast traffic). (The setup might seem a little bit involved and I don't remember the exact reasons for every design decision. ...
- 161
0 votes
0 answers
1k views
Router using smcroute stops routing multicast after some time
I have a problem with multicast routing on a "from scratch" (Debian, not LFS ;)) linux router/firewall. At home I've set up a user and a server net. Between the two is a router/firewall (...
0 votes
0 answers
840 views
High CPU usage on Cisco WS-4900M by multicast(PIM-SM)
Good evening I have a network with few Cisco routers (WS-4900M and 7606(as main core)) on backbone network and different connected to them l3 switches as client access routers, which receives igmp ...
2 votes
1 answer
606 views
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 ...
- 151
0 votes
1 answer
82 views
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 ...
- 249
0 votes
0 answers
3k views
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 ...
- 101
2 votes
1 answer
2k 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 ...
- 143
2 votes
1 answer
3k views
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 ...
google-cloud-platform
0 votes
0 answers
427 views
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 |...
- 219
1 vote
1 answer
2k views
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 ...
- 219
2 votes
1 answer
5k views
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 ...
- 506
0 votes
1 answer
6k views
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 ...
- 111
0 votes
0 answers
148 views
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. ...
1 vote
2 answers
684 views
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. ...
- 441
0 votes
0 answers
243 views
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 ...
- 1
0 votes
1 answer
2k views
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 ...
- 3