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AAM1212-51/53 Series User’s Guide
Chapter 17 IGMP
149
C
H A P T E R
17
IGMP
This chapter describes the
IGMP
screens.
17.1 IGMP
Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender to 1
recipient) or Broadcast (1 sender to everybody on the network). Multicast delivers IP packets
to just a group of hosts on the network.
IGMP (Internet Group Multicast Protocol) is a network-layer protocol used to establish
membership in a multicast group - it is not used to carry user data. See RFC 1112 and RFC
2236 for information on IGMP versions 1 and 2, respectively.
17.2 IP Multicast Addresses
In IPv4, a multicast address allows a device to send packets to a specific group of hosts
(multicast group) in a different sub-network. A multicast IP address represents a traffic
receiving group, not individual receiving devices. IP addresses in the Class D range (224.0.0.0
to 239.255.255.255) are used for IP multicasting. Certain IP multicast numbers are reserved by
IANA for special purposes (see the IANA web site for more information).
17.2.1 IGMP Snooping
A layer-2 switch can passively snoop on IGMP Query, Report and Leave (IGMP version 2)
packets transferred between IP multicast routers/switches and IP multicast hosts to learn the IP
multicast group membership. It checks IGMP packets passing through it, picks out the group
registration information, and configures multicasting accordingly. IGMP snooping allows the
AAM1212 to learn multicast groups without you having to manually configure them.
The AAM1212 forwards multicast traffic destined for multicast groups (that it has learned
from IGMP snooping or that you have manually configured) to ports that are members of that
group. The AAM1212 discards multicast traffic destined for multicast groups that it does not
know. IGMP snooping generates no additional network traffic, allowing you to significantly
reduce multicast traffic passing through your device.
17.2.2 IGMP Proxy
To allow better network performance, you can use IGMP proxy instead of a multicast routing
protocol in a simple tree network topology.
Содержание AAM1212-51
Страница 1: ...AAM1212 51 53 ADSL2 module of IES 1000 User s Guide Version 3 52 Edition 1 8 2006...
Страница 2: ...AAM1212 51 53 Series User s Guide 2...
Страница 24: ...AAM1212 51 53 Series User s Guide 24 Table of Contents...
Страница 36: ...AAM1212 51 53 Series User s Guide 36 List of Tables...
Страница 54: ...AAM1212 51 53 Series User s Guide 54 Chapter 3 Front Panel...
Страница 61: ...AAM1212 51 53 Series User s Guide Chapter 4 Introducing the Web Configurator 61 Figure 21 Logout...
Страница 62: ...AAM1212 51 53 Series User s Guide 62 Chapter 4 Introducing the Web Configurator...
Страница 68: ...AAM1212 51 53 Series User s Guide 68 Chapter 5 Initial Configuration...
Страница 84: ...AAM1212 51 53 Series User s Guide 84 Chapter 7 System Information...
Страница 90: ...AAM1212 51 53 Series User s Guide 90 Chapter 9 User Account...
Страница 96: ...AAM1212 51 53 Series User s Guide 96 Chapter 10 Switch Setup...
Страница 98: ...AAM1212 51 53 Series User s Guide 98 Chapter 11 IP Setup...
Страница 100: ...AAM1212 51 53 Series User s Guide 100 Chapter 12 ENET Port Setup...
Страница 132: ...AAM1212 51 53 Series User s Guide 132 Chapter 14 xDSL Profiles Setup...
Страница 140: ...AAM1212 51 53 Series User s Guide 140 Chapter 15 xDSL Line Data...
Страница 148: ...AAM1212 51 53 Series User s Guide 148 Chapter 16 VLAN...
Страница 166: ...AAM1212 51 53 Series User s Guide 166 Chapter 19 Multicast VLAN...
Страница 190: ...AAM1212 51 53 Series User s Guide 190 Chapter 26 DHCP Snoop...
Страница 198: ...AAM1212 51 53 Series User s Guide 198 Chapter 27 2684 Routed Mode...
Страница 204: ...AAM1212 51 53 Series User s Guide 204 Chapter 28 PPPoA to PPPoE...
Страница 220: ...AAM1212 51 53 Series User s Guide 220 Chapter 33 Syslog...
Страница 228: ...AAM1212 51 53 Series User s Guide 228 Chapter 34 Access Control...
Страница 238: ...AAM1212 51 53 Series User s Guide 238 Chapter 36 Alarm...
Страница 246: ...AAM1212 51 53 Series User s Guide 246 Chapter 38 Diagnostic...
Страница 270: ...AAM1212 51 53 Series User s Guide 270 Chapter 41 Commands...
Страница 278: ...AAM1212 51 53 Series User s Guide 278 Chapter 42 Command Examples...
Страница 286: ...AAM1212 51 53 Series User s Guide 286 Chapter 43 Alarm Commands...
Страница 328: ...AAM1212 51 53 Series User s Guide 328 Chapter 48 Packet Filter Commands...
Страница 334: ...AAM1212 51 53 Series User s Guide 334 Chapter 49 IP Commands...
Страница 344: ...AAM1212 51 53 Series User s Guide 344 Chapter 51 SNMP...
Страница 380: ...AAM1212 51 53 Series User s Guide 380 Chapter 52 ADSL Commands...
Страница 406: ...AAM1212 51 53 Series User s Guide 406 Chapter 53 Virtual Channel Management...
Страница 412: ...AAM1212 51 53 Series User s Guide 412 Chapter 54 ACL Commands...
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