255.255.255. BECAUSE ONE CLASS D ADDRESS IDENTIFIES AN ENTIRE GROU...

238. - MICROSOFT PRESS MCSA MCSE SELF PACED TRAINING KIT EXAM 70 - 293 PHẦN 4 PPT 238. - MICROSOFT PRESS MCSA MCSE SELF PACED TRAINING KIT EXAM 70 - 293 PHẦN 4 PPT
MICROSOFT PRESS MCSA MCSE SELF PACED TRAINING KIT EXAM 70 - 293 PHẦN 4 PPT

238.255.255.255. Because one Class D address identifies an entire group of systems, the

source computer requires only a single transmission to send a message to the entire group.

Members of a multicast group can be located on any LAN in an internetwork and are

still accessible with a single transmission. However, for the transmission to reach the

entire multicast group, the routers on the network must know which hosts are mem-

bers of the group, in order to forward messages to them.

Off the Record

Most of the routers on the market today, including the Routing and Remote

Access service in Windows Server 2003, support IP multicasting.

Computers that will be members of a multicast host group must register themselves

with the routers on the local network, using the Internet Group Management Protocol

(IGMP). To support multicasting, all the members of the host group and all the routers

providing access to the members of the host group must support

.

IGMP

Off the Record

All the Windows operating systems that include a TCP/IP client include

support for IGMP.

Lesson 2 Static and Dynamic Routing

5

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21

To receive all the IP multicast traffic on the network, the network interface adapters in

a router must support a special mode called multicast promiscuous mode. Unlike pro­

miscuous mode, in which the network interface adapter processes all incoming pack­

ets, multicast promiscuous mode has the network interface adapter process all

incoming packets with the multicast bit (that is, the last bit of the first byte of the des­

tination hardware address) set to a value of 1.

Planning

Most network interface adapters on the market support multicast promiscuous

mode, but make sure that the adapters in your routers have this support if you intend to use

multicasting on your network.

To support multicasting on a large internetwork, the routers must be able to share their

information about host group memberships. To do this, the routers use a multicast

routing protocol, such as the Distance Vector Multicast Routing Protocol (DVMRP), the

Multicast Open Shortest Path First (MOSPF) protocol, or the Protocol Independent Mul­

ticast (PIM) protocol. The Routing and Remote Access service in Windows Server 2003

does not include support for these, or any, multicast routing protocols other than the

IGMP routing protocol component, but a Windows Server 2003 router can run a third-

party implementation of such a protocol.

Practice: Installing RIP

In this practice, you configure RRAS to function as a LAN router and then install and

configure the RIP routing protocol. If you are working on a network, your server will

be able to exchange routing table information messages with other RIP routers on the

same LAN.