3Com S7902E, Руководство по настройке

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1-2
Figure 1-1 Before and after MLD snooping is enabled on the Layer 2 device
IPv6 multicast packet transmission
without MLD Snooping
Source
Multicast router
Host A
Receiver
Host B
Host C
Receiver
IPv6 multicast packets
Layer 2 switch
IPv6 multicast packet transmission
when MLD Snooping runs
Source
Multicast router
Host A
Receiver
Host B
Host C
Receiver
Layer 2 switch
MLD snooping forwards multicast data to only the receivers requiring it at Layer 2. It brings the following
advantages:
z
Reducing Layer 2 broadcast packets, thus saving network bandwidth.
z
Enhancing the security of multicast traffic.
z
Facilitating the implementation of per-host accounting.
Basic Concepts in MLD Snooping
MLD Snooping related ports
As shown in Figure 1-2 , Router A connects to the multicast source, MLD snooping runs on Switch A and
Switch B, Host A and Host C are receiver hosts (namely, IPv6 multicast group members).
Figure 1-2 MLD snooping related ports
Router A Switch A
Switch B
GE2/0/1 GE2/0/2
GE2/0/3
GE2/0/1
GE2/0/2
Receiver
Receiver
Host A
Host B
Host C
Host D
Source
IPv6 multicast packets
Router port
Member port
Ports involved in MLD snooping, as shown in Figure 1-2 , are described as follows: