Cisco Systems 3750E ユーザーズマニュアル
24-7
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02
Chapter 24 Configuring IGMP Snooping and MVR
Configuring IGMP Snooping
IGMP Snooping and Switch Stacks
IGMP snooping functions across the switch stack; that is, IGMP control information from one switch is
distributed to all switches in the stack. (See
distributed to all switches in the stack. (See
for more information
about switch stacks.) Regardless of the stack member through which IGMP multicast data enters the
stack, the data reaches the hosts that have registered for that group.
stack, the data reaches the hosts that have registered for that group.
If a switch in the stack fails or is removed from the stack, only the members of the multicast group that
are on that switch will not receive the multicast data. All other members of a multicast group on other
switches in the stack continue to receive multicast data streams. However, multicast groups that are
common for both Layer 2 and Layer 3 (IP multicast routing) might take longer to converge if the stack
master is removed.
are on that switch will not receive the multicast data. All other members of a multicast group on other
switches in the stack continue to receive multicast data streams. However, multicast groups that are
common for both Layer 2 and Layer 3 (IP multicast routing) might take longer to converge if the stack
master is removed.
Configuring IGMP Snooping
IGMP snooping allows switches to examine IGMP packets and make forwarding decisions based on
their content. These sections contain this configuration information:
their content. These sections contain this configuration information:
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Default IGMP Snooping Configuration
shows the default IGMP snooping configuration.
Table 24-3
Default IGMP Snooping Configuration
Feature
Default Setting
IGMP snooping
Enabled globally and per VLAN
Multicast routers
None configured
Multicast router learning (snooping) method
PIM-DVMRP
IGMP snooping Immediate Leave
Disabled
Static groups
None configured
TCN
1
flood query count
2
TCN query solicitation
Disabled