Igmp Snooping And Switch Stacks; Configuring Igmp Snooping; Default Igmp Snooping Configuration - Cisco Catalyst 3560-X Software Configuration Manual

Chapter 1 Configuring IGMP Snooping and MVR

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
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.
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.

Configuring IGMP Snooping

IGMP snooping allows switches to examine IGMP packets and make forwarding decisions based on the
content. These sections contain this configuration information:
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Default IGMP Snooping Configuration

Table 1-3
Feature
IGMP snooping
Multicast routers
Multicast router learning (snooping) method
IGMP snooping Immediate Leave
Static groups
TCN
TCN query solicitation
IGMP snooping querier
IGMP report suppression
1. TCN = Topology Change Notification
OL-25303-03
Default IGMP Snooping Configuration, page 1-7
Enabling or Disabling IGMP Snooping, page 1-8
Setting the Snooping Method, page 1-8
Configuring a Multicast Router Port, page 1-9
Configuring a Host Statically to Join a Group, page 1-10
Enabling IGMP Immediate Leave, page 1-11
Configuring the IGMP Leave Timer, page 1-11
Configuring TCN-Related Commands, page 1-12
Configuring the IGMP Snooping Querier, page 1-14
Disabling IGMP Report Suppression, page 1-15
Default IGMP Snooping Configuration
1
flood query count
Chapter 1, "Managing Switch Stacks,"
Default Setting
Enabled globally and per VLAN
None configured
PIM-DVMRP
Disabled
None configured
2
Disabled
Disabled
Enabled
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
Configuring IGMP Snooping
for more information
1-7