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

2
votes
4answers
947 views

Should a small company block multicast on their network?

Currently, the firewall at a small company is blocking multicast on their network. Should they continue to block multicast? Are there security concerns to unblocking it? Are there benefits to ...
2
votes
2answers
2k views

Multicast over SSH

I have two LANs: 10.x.x.x and 192.x.x.x. On each LAN I have a Linux machine (10.x.x.5 and 192.x.x.5) but they are not routers. I can open ssh from 192.x.x.5 to 10.x.x.5. There are multicast udp ...
0
votes
1answer
13k views

How do I add a multicast route in Windows 7?

I have 2 interfaces on my desktop: one in a multicast enabled vlan, that has access to some udp streams, but otherwise unrouted, and one with internet access, but no multicast. If only the multicast ...
1
vote
2answers
444 views

Multicasting for WDS

I want to install a Windows 7 image on 40-something computers without touching 'em I have a WDS server, an image captured, and an answer file setup. I go to create a multicast transmission out of ...
0
votes
2answers
258 views

Unicast through Multicast

Suppose I have Multicast group with a group ID and I want to send packet to only one of the group members(as we are doing in anycasting). Is it possible? If yes then how?
2
votes
1answer
147 views

Multicast over 802.11b wireless

How do wireless routers behave with regards to multicast traffic? Given that nature of the shared physical medium routing to specific ports is not possible. Therefore, are mutlticast packets ...
3
votes
2answers
2k views

IGMP/Multicast routing in Linux

I need to route IGMP/Multicast traffic across two networks. I have a Linux box with two NICs, one public, one private. Need devices on the private network to flow to public. I'm pretty certain I ...
1
vote
1answer
351 views

Windows Deployment workflow

I've been digging around and getting WDS, WAIK, and the Deployment Workbench all configured and installed on a server we'll be using to roll images out to classrooms. I want to make sure I understand ...
1
vote
1answer
239 views

How to get UCARP to work over wireless?

I would like to get ucarp to work over a wireless (802.11g) interface, but the packages is never seen on the wired end. The setup looks like this: Box1 (10.0.0.11, wireless) -- AP -- (10.0.0.13, ...
0
votes
2answers
374 views

How to restore with multicast 3 systems: Windows 7, Windows 2008 and Linux?

We have used an old version of Norton Ghost to do backups and restores of computers. There are few groups of computers with the same hardware and we have used multicast. We have had Windows XP, ...
0
votes
2answers
764 views

Selecting interface for multicast traffic?

How do I specify an interface for multicast traffic? I need to connect to multicast group through vlan interface (tcpdump show traffic there) but I believe that IGMP request are sent throug eth0. ...
4
votes
4answers
4k views

Multicast File Transfers

I'm looking for some multicast file transfer software. Do you have any suggestions? Must be "quickly implementable", i.e. no Tivoli or other stuff that requires a massive infrastructure. Must run on ...
2
votes
3answers
1k views

Why are my listener-less multicast packets affecting Wifi performance?

I've got a program that sends out a IPv6 multicast packet (to ff12::2:0:8afb:382b:c053:85f%en1) every 50ms. I've got it running on a very simple single-computer LAN (Mac mini <-wifi-> Linksys wifi ...
0
votes
1answer
551 views

JBoss without multicast?

Does anyone know if it is possible to run JBoss as a cluster using only unicast, no multicast? More importantly, does anyone have experience actually getting this to work?
15
votes
5answers
24k views

Linux Kernel not passing through multicast UDP packets

Recently I've set up a new Ubuntu Server 10.04 and noticed my UDP server is no longer able to see any multicast data sent to the interface, even after joining the multicast group. I've got the exact ...
2
votes
1answer
452 views

Clustering on cloud/VPS providers

I'm wondering if anyone can give some clustering recommendations to me. I'm currently on Linode, which I'm impressed and happy with, but they (along with just about every other VPS provider I know of) ...
1
vote
1answer
1k views

Lots of artifacts while streaming HD content with VLC 0.9.9 on CentOS

I'm trying to stream (multicast) a x264 encoded file using VLC. This in itself succeeds, but the stream has a huge lot of artifacts. This seems to suggest that the data cannot be transported fast ...
2
votes
1answer
618 views

Multicast accross the subnets

My application sends some UDP packets on a multicast address. In our office we have 3 subnets connected via routers. Sitting in my subnet I'm able to ping the IP of the other subnet. Will multicast ...
1
vote
2answers
934 views

Multicast image restoration with adaptive speed

I'm curious to know if there are any tools for restoring disk images (or even transferring files) via multicast -- for any platform, especially if the project has source available -- where the ...
1
vote
2answers
449 views

video streaming infrastructure advice

We would like to set-up a live video-chat web site and are looking for basic recomendations for software and hardware set-up. Here are the particulars on the site: Most streams will be broadcast ...
1
vote
1answer
986 views

Create NSC-File for multicast streaming with Windows Media Streaming

For streaming multicast I need to create a NSC-file for the players - this file is pseudo-coded by Microsoft. Now I need to create this file for each proxy-publishingpoint. Is there any way to stream ...
0
votes
2answers
358 views

UPD Multicast (Class D) = How can this be routed over the internet?

is there a simple way (without setting up a local network via VPN) to route UPD Multicast Packets (224.0.0.0 to 239.255.255.255) from one server to another server (both residing in completely ...
1
vote
3answers
3k views

Windows Network Load Balancing on ESX Cluster with Dell PowerConnect stacks

We recently switched out our Cisco 6500 core switch for a pair of Dell PowerConnect 6248 stacks. Since then, our Network Load Balanced Sharepoint, which runs on two virtual machines on an ESX cluster ...
4
votes
1answer
174 views

Calculating and billing IP multicast usage on the Internet

I've been searching for the reasons why IP multicast isn't widely supported on the Public Internet, and a commonly-cited reason is the difficulty ISPs have in tracking Multicast usage for later ...
2
votes
1answer
1k views

Confusion about HSRP Groups

If I have a router that has several LANs on it, and each of these LAN is attached to a second router, do I need to use different HSRP groups for each LAN? With this set up, each virtual gateway will ...
2
votes
1answer
3k views

How DNS service discovery, multicast DNS and Bonjour are related?

I am a bit lost in the terminology. I wanted to start to use Bonjour. As the first step, I tried to find an easy way to use it. And I thought that I, probably, can call Bonjour from the command line ...
3
votes
4answers
1k views

Multicast in Rackspace cloud

On Amazon EC2, I cannot use multicast, but how about rackspace cloud? It would be very beneficial to be able to use multicast as most clustering protocols rely on it...
10
votes
4answers
1k views

How common are dropped packets in communications within a data center?

Let's say I have 2 machines in the same data center but not necessarily in the same rack. How common would dropped packets be when sent using UDP between these two machines? I'm asking under the ...
2
votes
2answers
692 views

Can a TCP/IP be efficiently multicast among clients without UDP

I have a high bandwidth application in which a server is to be producing data a rate of ~300Mb/s on a gigabit network. Is there a way other than UDP to multicast to 1 to 10 clients through a reliable ...
1
vote
3answers
540 views

Cisco multicast configuration

I'm on an isolated (for now) catalyst 3560e. I have a multicast source, which when enabled, causes flooding to all switch interfaces. I have a second different multicast source, which does not cause ...
0
votes
1answer
1k views

What are good host firewall rules to allow UDP multicast?

I have a system with a restrictive firewall that will be participating in UDP multicasting (sending and receiving). What's a good set of rules to make the host's firewall allow this? This is my ...
0
votes
2answers
3k views

Using Clonezilla Server Edition with multiple multicast restore operations

I run a computer refurbishing operation for a local non-profit I am a part of. I have been looking into using Clonezilla to do network-based image-restoration. I am very interested in the multicast ...
2
votes
3answers
14k views

How to block all multicast traffic travelling through a Cisco Catalyst 3750

Something changed today. I can't seem to track down what, but one of our 3750s decided that it was going to forward all the multicast traffic it saw from the ghost server across every VLAN it has. ...
3
votes
4answers
6k views

Why does multicasting make the WAN inaccessible?

I'm hesitant to ask this question as I may not be able to perform the diagnostic steps to find out what is up, but: I need to re-image a lab in a school, possibly during school hours. I am using a ...
1
vote
1answer
1k views

What affects multicast rates?

I'm experimenting the Trinity Rescue Kit (TRK) http://trinityhome.org/Home/index.php?wpid=1&front%5Fid=12 and it's ability to clone hard disks to many computers at one time using multicast ...
2
votes
1answer
883 views

Video-on-demand/surveillance server setup

I'm planning to set up a service that would allow people to connect their ip-cameras to and watch video embedded into a website. Scheduled saving and replaying would also be available. What hardware ...
1
vote
3answers
2k views

DVMRP vs PIM-DM multicast protocols

Recently I've started to read RFCs of different multicast standards and came out to the question, which is not totally clear for me. I'm trying to compare DVMRP vs PIM-DM routing protocols in order to ...
3
votes
11answers
2k views

Most resilient form of (private) DNS clustering?

I'm working on a setup with two datacenters linked by a MAN (bridged) and everything is doubled between them, in fail-over mode with RedHat Cluster, DRBD and that kinf of things. I have one DNS ...