Can anyone recommend a textbook or online resource for learning the current state of multicast technology, from the perspective of a network engineer/designer? The ‘bible’ that most of my more experienced colleagues seem to use is Developing IP Multicast Networks, by Williamson, which was published in 1999. Has multicast technology really not moved on since then? Or are the same principles and protocols still in use, without only incremental changes not warranting a newer text? [...]Continue Reading »
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 server for each location, but it turns out that having both in /etc/resolv.conf doesn’t help much; if one goes down, the client waits 10s or so half of the time. In other words, it’s using them for load balancing, not [...]Continue Reading »
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 understand which one is better, which one producing less multicast message while establishing route and during routing process at all. And which one of them is able to produce more sophisticated source tree. Can you, please help me to figure [...]Continue Reading »
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. I’ve tried writing a simple access group that consists of the following: access-list 100 deny ip any 220.127.116.11 0.0.0.255 access-list 100 permit ip any any I apparently mistakenly assumed that once applied to an interface that it would [...]Continue Reading »
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 functionality provided by Clonezilla. I want to do multiple multicast restorations at the same time, but Clonezilla does not currently support that. It uses udpcast (udp-sender/udp-receiver) as its multicast server. Current it uses a hard-coded IP and port for the multicast server [...]Continue Reading »
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 flooding, it only gets delivered to the sinks who request it. The second case leads me to believe the switch IGMP is configured properly, but what could be different about the first stream? I thought multicast/IGMP was ‘I only get the stream [...]Continue Reading »
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 transport mechanism? This application is very much like streaming video in that the continuity of the stream is more important than the reliability. The current application is a bit slower and uses UDP combined with [...]Continue Reading »
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 assumption that since there are only a few switches at most between the machines that the packets will not be dropped at all. How common is out-of-order packet arrival within the same data center? My assumption is there’s but [...]Continue Reading »
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… Multicast isn’t currently allowed on Rackspace Cloud Servers. The traffic volume of multicast traffic ends up overloading the switching layer and it degrades network performance for all traffic. Check more discussion of this question. Bookmark on Delicious Digg this post Recommend on Facebook share via [...]Continue Reading »
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 to register and discover services. When I asked other people how to do it, I was told about mDNS (which works for Mac and Linux but not Windows). People also told me that [...]Continue Reading »
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