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Multicast addressing supports dynamic membership, under which individual computers can join or leave a multicast group at any time. Group membership is not limited by size, and computers are not restricted to membership in any single group.
On all IP networks, each computer must first be configured with its own unicast IP address. After assigning this unicast address, you can co 949r176j nfigure the computer to support a multicast address. A multicast group of computers shares the same multicast IP address. IPv4 multicast addresses range, in dotted decimal notation, from 224.0.0.0 through 239.255.255.255 (224.0.0.0/4). Such a multicast group also uses a MAC-layer multicast address, which allows all devices to filter unsolicited multicast traffic at the link layer. Ethernet addresses reserved for multicasting range from 01-00-5E-00-00-00 through 01-00-5E-7F-FF-FF.
Typically, you specify IP address ranges for multicast scopes on your MADCAP server in the following ways:
Administrative scoping is designed for multicast IP addresses used privately on your intranet. You use the 239.192.0.0 range of the multicast (Class D) address space with a subnet mask of 255.252.0.0. This is known as the IPv4 Organization Local Scope. It provides 262,144 group addresses (2 ) for use in all subnets on your network. For more information about administrative scoping, see RFC 2365, "Administratively Scoped IP Multicast."
Global scoping is designed for multicast IP addresses used on the Internet. You use the 233.0.0.0 range of the multicast address space. Global addresses are allocated in the following way:
IANA (or another network registry) allocates and reserves the first 8 bits of the range (the "233" portion).
The next 16 bits are based on your
Autonomous System (AS) number. For information about obtaining your existing AS number or acquiring a new one, see "Using Multicast Scopes" in
Help and
The last 8 bits provide the IP address range from which to configure any multicast scopes for group addresses that you want to use publicly on the Internet. Use a subnet mask of 255.255.255.0.
For more information about global scoping, see RFC 3180, "GLOP Addressing in 233/8." For more information about AS numbering, see RFC 1930, "Guidelines for Creation, Selection, and Registration of an Autonomous System (AS)."
On participating clients, install and configure the appropriate MADCAP-aware hardware and software. For example, for video conferencing, install video conferencing software and a video camera, sound card, and audio headset.
Standards for the multicast transmission of a data stream between the subnets of an internetwork include RFC 1112, "Host Extensions for IP Multicasting"; RFC 2236, "Internet Group Management Protocol, Version 2"; and the Internet Draft "Internet Group Management Protocol, Version 3." Such standards instruct routers how and where to route multicast traffic.
For more information about IP multicasting, including multiple supported multicast configurations, see the Internetworking Guide of the Windows Server 2003 Resource Kit (or see the Internetworking Guide on the Web at https://www.microsoft.com/reskit), and for information about Windows Server 2003 TCP/IP, see the Networking Guide of the Windows Server 2003 Resource Kit (or see the Networking Guide on the Web at https://www.microsoft.com/reskit).
In addition to the IPv4 stack installed by default, Windows Server 2003 and Windows XP include an IPv6 protocol stack that you can use to test IPv6, to explore IPv6-enabled applications, and to prepare for possible eventual migration to a native IPv6 infrastructure.
It is expected that IPv4 and IPv6 will coexist on enterprise networks for a number of years. Depending on their needs, some organizations might continue to use IPv4 exclusively, some will migrate slowly while running both IPv4 and IPv6 in the interim, and some will maintain IPv4 in one or more sections of their organization and implement IPv6 in other sections.
To ensure that your organization makes best use of IPv6 capabilities with the least administrative overhead, include a plan for introducing IPv6 into the design for your TCP/IP network. To prepare to introduce IPv6, you must explore the new functionality introduced by IPv6, plan IPv6 addressing, plan how to route IPv6 traffic over an existing IPv4 infrastructure or an IPv6 infrastructure, decide whether to deploy DNS dynamic update, and decide whether to deploy PortProxy to enable IPv4 applications (where possible) for IPv6. Figure 1. shows each task in the planning process.
Figure 1.15 Introducing IPv6 on Your Network
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