
210
C
HAPTER
11: IP M
ULTICAST
F
ILTERING
WITH
IGMP
Key Concepts
IGMP plays a specific role in the overall delivery process for IP multicast
traffic. Before you modify IGMP parameters in a Layer 2 Switching
Module, review the following key concepts about IP multicast packets.
Devices That
Generate IP Multicast
Packets
Application sources (usually servers) generate IP multicast packets as the
way to deliver their information (such as a video stream) to interested
hosts (such as PC end stations).
Network devices generate IP multicast packets as the way to
communicate with each other to establish a delivery path. These packets
are issued by specific supporting protocols, such as IGMP.
Group Addresses and
Group Members
An IP multicast packet differs from a unicast packet by the presence of a
multicast group address
in the destination address field of the IP header.
Each application uses a unique group address, and hosts refer to these
group addresses when they tell network devices which IP multicast
transmissions they want to receive. In doing so, hosts become
group
members
. Hosts can join and leave one or more groups at any time.
Communication
Protocols
To coordinate an efficient, loopfree delivery path for IP multicast packets,
certain protocols are used among network devices and hosts:
■
A multicast routing protocol such as Distance-Vector Multicast
Routing Protocol (DVMRP) is used between routers (if routers exist
between sources and group members).
■
A protocol such as IGMP is used between routers, switches, and hosts
in each subnetwork or broadcast domain.
See Figure 9.
Содержание 4007
Страница 1: ...http www 3com com Switch 4007 Implementation Guide Release 3 0 5 Part No 10013673 Published May 2000 ...
Страница 36: ...36 ABOUT THIS GUIDE ...
Страница 37: ...I UNDERSTANDING YOUR SWITCH 4007 SYSTEM Chapter 1 Configuration Overview ...
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Страница 50: ...50 CHAPTER 1 CONFIGURATION OVERVIEW ...
Страница 52: ......
Страница 70: ...70 CHAPTER 3 INSTALLING MANAGEMENT MODULES ...
Страница 110: ...110 CHAPTER 4 CONFIGURING AND USING EME OPTIONS ...
Страница 130: ...130 CHAPTER 5 MANAGING THE CHASSIS POWER AND TEMPERATURE ...
Страница 222: ...222 CHAPTER 11 IP MULTICAST FILTERING WITH IGMP ...
Страница 240: ...240 CHAPTER 13 RESILIENT LINKS ...
Страница 304: ...304 CHAPTER 14 VIRTUAL LANS VLANS ...
Страница 350: ...350 CHAPTER 15 PACKET FILTERING ...
Страница 506: ...506 CHAPTER 19 OPEN SHORTEST PATH FIRST OSPF ROUTING ...
Страница 534: ...534 CHAPTER 20 IPX ROUTING ...
Страница 612: ...612 CHAPTER 22 QOS AND RSVP ...
Страница 656: ...656 CHAPTER 23 DEVICE MONITORING ...
Страница 657: ...IV REFERENCE Appendix A Technical Support Index ...
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