As promised, here is the second article on IP Multicast. This one specifically cover the addressing, which evolved in parallel to the high number of standards that define what multicast is today. I tried to compile a list that is as comprehensive as possible; if you find something that I omitted, please let me know, I will be glad to update this article accordingly. I hope this article will help you to quickly and efficiently review all or specific part of the multicast addressing.
This article is the first of a series about IP multicast. Multicast is a great technology which you may come across as an network engineer. Unfortunately, it's still a frequently overlooked technology due to its alleged complexity. In fact, multicast addressing is no more complex than unicast. Multicast routing is only about understanding a few basic principles, but once you get them, you can easily design and implement very large and sparse multicast networks. Troubleshooting is certainly more difficult because of the stateful nature of multicast routing, but with proper use of tools and procedures, you can quickly figure out where problems lies and how to solve them. As these aspects are very different from each other, I will cover them in separate articles. Here's the first article; an overview of IP multicast.
Sometimes, you do not have access to enough public address space to number all your subnets. This is especially recurrent in virtualized environments where network segmentation is a natural design choice. In such environments, you may have several VLANs and routing instances (call them routing domains, or contexts, depending of the vendor terminology you're familiar with), and for each, comes a unique set of subnets. Every network operator knows how painful IP address management is, and we all want to avoid renumbering our network, especially if the following account for hundreds, if not thousands of subnets. You certainly also figured out that Network Address Translation (NAT) could help in this manner, but do you know its benefits could be as well applied to the IPv6 world?