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 ...

learn more… | top users | synonyms

1
vote
1answer
603 views

Is IGMP multicast traffic to a Xen VM host legitimate?

I run two Xen/CentOS 6.5 based VMs, both hosted by the same company, but connected to different networks (basic /24s w/ a single gateway at .1) in different physical locations. I developed an iptables ...
0
votes
2answers
601 views

Running WDS with multicast enabled from within a Hyper-V cluster

I'm attempting to run a multicast installation with WDS over my network, where WDS is hosted in a virtual machine in a Hyper-V cluster. I believe we've paved over most of the network-related issues - ...
-1
votes
2answers
194 views

What is the equivalent of 127.255.255.255 for OS/X machines so I can test broadcast udp packets without a network? [duplicate]

I am trying to test my program that makes use of broadcast UDP (not multicast!). In Linux, I can use the 127.255.255.255:64651 address and everything works beautifully, in other words, I send a packet ...
2
votes
1answer
380 views

Setting up NLB in a VLAN

I have a network layout like this (ESXi hosts): Internal Network + +-----------------+ ...
1
vote
1answer
892 views

How to make a Cisco AP1142N speak Bonjour?

I have an autonomous Cisco access point (model AP1142N) and an Apple TV that are on the same physical and logical network. Bonjour does not work across the access point — both WiFi-to-WiFi and ...
1
vote
0answers
148 views

ARP Tables on Windows vs Linux

I noticed on Windows Server 2008, Windows Server 2008 R2, and Windows 7 that IP multicast groups joined by a computer are recorded in the ARP table as static addresses automatically. However, the same ...
1
vote
0answers
239 views

How do get multicast to work on a Cisco AP1240?

I have a Cisco AP1142N in standalone mode acting as a simple AP. On the wired segment of the LAN, there is an Apple TV that is used to mirror laptop screens to a large TV screen. As long as clients ...
0
votes
2answers
288 views

Can heavy UDP traffic create network congestion?

I have three IP addresses using the same gateway. Two of them are configured as a cluster with multicast address setup. If there is a heavy UDP traffic between those two, can that affect the network ...
0
votes
2answers
36 views

unicast traffic on windows server

I have three servers with IP addresses (10.15.23.23, 10.15.23.24, 10.15.23.25). Server 1 and Server 2 have Tomcat installed and are configured as a cluster listening on a multicast IP address ...
0
votes
1answer
495 views

diagnostic multicast issue using wireshark

I have a network that is setup for multicast traffic. My setup is the following -Machine A : a server generates multicast traffic. -Machine A : few clients subscribing to that multicast traffic ...
0
votes
1answer
2k views

Multicast Listener Report Message v2

I run an ICMPv6 protocol and I have made a capture using wireshark. In the capture I have some Multicast Listener Report Message v2. Some of the has the source ip, the ipv6 link local address, but ...
0
votes
1answer
173 views

DNS resolution on multicast IP

Edit: Looks like ns lookup on some mcast IP doesn't not get a failed answer right away. Any suggestion? I have two env, the new one we built is running BIND on linux. When running lsof or tcpdump, ...
1
vote
0answers
184 views

linux kernel configuration to filter multicast traffic based on interface

I have two virtual interfaces (eth0.2, eth0.3) in my PC. I am sending multicast data from eth0.2 to eth0.2. Multicast data is received in eth0.2 but also received in eth0.3, the other virtual ...
-1
votes
1answer
90 views

How multicasting grouping address works ? How can I add nodes to the existing group of multicasting group? [closed]

I am a newbie to the networking and working on the 6LoWPAN protocol and I am trying to get the multicasting to work on the network. But I don't know how to create group for multicasting and how to ...
0
votes
0answers
668 views

How to enable multicast routing in TMG 2010?

I have a TMG 2010 firewall between some office networks, which handles routing and firewalling; I need to let some application-specific multicast traffic flow between these networks; this is UDP ...
-1
votes
2answers
265 views

how to receive MAC multicast packets based on VLAN interface?

can any one pls help me in the following question. Background : Two PC's(PC1 n PC2) with two VLAN interfaces in each (eth0.2 and eth0.3) respectively.The PC's are connected by WRT54GL router in ...
1
vote
1answer
376 views

Enable multicast on dummy interface on startup

I have a dummy interface on a Centos 6.3 machine which I would like to use for multicast traffic. The problem is it does not come up with the MULTICAST option by default; I need to manually add it ...
2
votes
3answers
555 views

Why would IGMP and MLD be required to forward unregistered packets to all ports?

First, a little background: My understanding is that the purpose of IGMP (and its IPv6 cousin, MLD) is to avoid wasted bandwidth by ensuring that multicast packets only get transmitted to ...
1
vote
1answer
386 views

If I have a process which is supposed to be receiving data from multicast, how can I check if it actually is?

I can check gstack, but just because I see the listener threads on the recv call does not mean that call is not returning. One other thing I thought was to do something like: netstat -lupe | grep ...
2
votes
1answer
317 views

is there a way to “multicast” a request with haproxy?

I have a configuration with a cloud of servers behind haproxy. Haproxy is loadbalancing between the servers. However there's some action that needs to be sent to each server. Currently I do it ...
3
votes
3answers
6k views

Should I create a multicast route on RHEL/CentOS for a blind sender?

A CentOS 5 system does not appear to come out-of-the-box with a route for multicast traffic. What it does appear to do is use a default route, if configured. In other words, a routing table like ...
0
votes
1answer
139 views

Is multicast appropriate for sending a copy of a video chat to a server?

I am creating a p2p video chat app using the libjingle/WebRTC code. I would like to collect a copy of these video conversations on our server for users to watch later - but I don't want to suck up too ...
2
votes
1answer
201 views

Does the IGMP querier have to be connected to the multicast source?

I've been reading Allied Telesis' guide on configuring IGMP, which has been quite enlightening so far. However, I'm still wondering whether the IGMP querier has to be connected directly to the ...
0
votes
2answers
4k views

Problems with multicasts in “iptables”

My question is related to multicasts and iptables. I want to allow ICMP and IGMP multicasts from the local VLAN 192.168.1.0/24 as well as from 0.0.0.0 on my CentOS machine, so I added the following ...
2
votes
2answers
789 views

Solaris doesn't know which MAC address to use to send an UDP multicast message

I have a pair of Solaris 10 boxes which are supposed to send multicast UDP packets to a group of hosts. One of them works just fine, whereas the other one does not. The problem with the second ...
5
votes
1answer
168 views

Why would I ever (really) want to implement dense mode when dealing with PIM routing?

I'm introducing some PIM routing into my network to make some multicast traffic available across routers. I have read a bit on PIM, sparse mode versus dense mode. After reading, I am trying to ...
2
votes
1answer
103 views

How does iptables determine which packets are multicast?

Are packets assumed to be multicast solely based on their ip address? I've been looking at the RFC 1112 and a quick scan doesn't appear to indicate any other flags on the ip packet.
2
votes
0answers
262 views

Manual Multicast forwarding with Linux router

I have a Linux router (Ubuntu). It is working well with unicast but with multicast routing/forwarding I have some trouble. The problem is that my hosts do not send igmp/mld messages thus the router ...
1
vote
0answers
2k views

Unable to ping multicast IP

Let me prefix this by saying I'm not entirely clear on how multicast works. I have the gist of it, but not the underlying functionality. A customer has configured a RHEL6 cluster between two Jboss ...
2
votes
2answers
673 views

MS NLB: why are multicast packets received by all servers on the LAN, not just members of the cluster

I have a MS NLB cluster (Win 2003) which includes just two hosts. The cluster is configured to use Multicast operation mode (not IGMP). For some reason I am seeing packets intended for the NLB ...
1
vote
0answers
100 views

How can I set up multicast tunnel between hosts on the same net

Dealing with AWS, where multicast packets won't travel even between systems on the same net (VPC). Generally, this is not specific to AWS, as this is generally possible in any network (i.e. you have a ...
0
votes
1answer
405 views

Icecast2 and multicast

Does anyone know if Icecast2 supports multicast? I've been searching for a while and I found nothing on neither docs or FAQ Thanks
-2
votes
1answer
47 views

Motorolla TeamBadge Issue [closed]

I have A setup of Motorolla EBW100 Team Badges (typical Walkie Talkie). My wifi is configured as Such that it has Multiple SSIDs For different Badges. Like in Floor A I want 10 Team Badges to work ...
2
votes
0answers
253 views

network leave/unscribe multicast group

I have debian based server where I need to subscribe a multicast. After doing it with headless mpalyer I can see the following: root@ca1:~# netstat -g IPv6/IPv4 Group Memberships Interface ...
1
vote
1answer
902 views

IP-Multicast difference between 224.0.0.1-255 and 239.0.0.0/8 block

Whats the difference between: Local subnetwork Addresses in the range 224.0.0.0 to 224.0.0.255 are individually assigned by IANA and designated for multicasting on the local subnetwork only. ...
1
vote
1answer
794 views

Multicast in private LAN with different subnets

after i read Multicast IP Addresses and Multicast accross the subnets I am confused. Configuration: I have two devices in the same network. They may not be in the same Subnet, but ...
0
votes
2answers
3k views

How to disable multicast on a single port

We just finished deploying 2 cisco SG300-28 switches in our network. We're building a voLANte video distribution network, so all ports were enabled to have multicasting support. The problem we face ...
23
votes
4answers
2k views

Pushing Large Files to 500+ Computers

I work with a team to manage 500-600 rented Windows 7 computers for an annual conference. We have a large amount of data that needs to be synced to these computers, up to 1 TiB. The computers are ...
1
vote
1answer
1k views

How to make sysctl network bridge settings persist after a reboot?

I am setting up a notebook for software demo purpose. The machine has 8GB RAM, a Core i7 Intel CPU, a 128GB SSD, and runs Ubuntu 12.04 LTS 64bit. The notebook is used as a KVM host and runs a few KVM ...
1
vote
1answer
379 views

Multicast File copy with Unicast responses

I'm trying to do some multicast big file copies over to remote clients on the other side of a satellite link. The idea is to minimize the amount of traffic going up to the satellite. I tried using ...
3
votes
1answer
4k views

Multicast doesn't seem to be working on RHEL 5.5

I'm trying to install Oracle Grid Infrastructure on two machines. Their documentation states: You must enable multicasting for the cluster on the IP address subnet ranges 224.0.0.0/24 and ...
0
votes
1answer
275 views

multicast streaming, too much network traffic?

I am thinking of switching our streaming servers to use multicasting instead of registering multiple clients and duplicating the streams manually on the server. It seems to work very well. However, I ...
2
votes
2answers
3k views

Can I test broadcast packets on a single machine?

I want to have a server sending broadcast UDP packets and two other clients, in the same machine, receiving them. Can I do that somehow? What IP address would I use? @gravyface gave me hope but I ...
5
votes
1answer
6k views

Why is pfSense blocking multicast traffic when it is explicitly enabled?

I have a pair of pfSense firewall/routers set up in CARP/XML Config cluster. On the LAN side, the switch also has a pair of servers running corosync/pacemaker/drbd. These are on a different ip ...
0
votes
3answers
1k views

Is there Muticast routing support on a Cisco 3750?

We have a switch (Cisco WS-C3750G-48TS) with only a C3750-IPBASE-M image (not a 'C3750-IPSERVICES-M' license). Is there any kind of multicast support here? All I need it to do is route multicast ...
0
votes
1answer
183 views

multicast network based on bridges between two hardware servers

+------------------------+ Internet +----------------------+ | Server_1 | | | Server_2 | | VPS1 ---- br0 __ | (router) | __ VPS4| ...
3
votes
1answer
86 views

Streaming root/source in multicasting sparse mode

I'd like to verify if I understand multicasting correctly. In a pim sparse-mode configuration, the RP rtr becomes the "root" of the stream for the rest of the configured routers. Does this mean that ...
8
votes
5answers
2k views

Is IPv6 multicast routable over the Internet?

As I understand it, public IPv6 addresses allocated by the IANA will have the prefix 2000::/3. These ip addresses will be routable through the Internet. IPv6 multicast addresses on the other side are ...
3
votes
1answer
2k views

How to monitor a UDP multicast stream on a cisco network, hopefully with SNMP

We have a LAN with 2x Cisco 4500's as gateways running HSRP. We're using Exterity HD IP Encoders to take HD video and put it onto the network as a multicast UDP stream (playable in VLC). I have a ...
1
vote
0answers
226 views

wdsmcast useage and deployment

I'm trying to use WDS multicasting to deploy an image. For some reason I can't get it to connect. Anyone know any guides on how to do this because I followed and few and none are working. I setup a ...