Users Guide

• A maximum of 1800 groups and 600 VLAN are supported.
• IGMP snooping is not supported on a default VLAN interface.
• IGMP snooping is not supported over VLAN-Stack-enabled VLAN interfaces (you must disable IGMP snooping on a VLAN
interface before conguring VLAN-Stack-related commands).
• IGMP snooping does not react to Layer 2 topology changes triggered by spanning tree protocol (STP).
• IGMP snooping reacts to Layer 2 topology changes multiple spanning tree protocol (MSTP) triggers by sending a general query
on the interface that comes in the FWD state.
Important Points to Remember for IGMP Querier
• The IGMP snooping Querier supports version 2.
• You must congure an IP address to the VLAN interface for IGMP snooping Querier to begin. The IGMP snooping Querier
disables itself when a VLAN IP address is cleared, and then it restarts itself when an IP address is reassigned to the VLAN
interface.
• When enabled, IGMP snooping Querier does not start if there is a statically congured multicast router interface in the VLAN.
• When enabled, IGMP snooping Querier starts after one query interval in case no IGMP general query (with IP SA lower than its
VLAN IP address) is received on any of its VLAN members.
• When enabled, IGMP snooping Querier periodically sends general queries with an IP source address of the VLAN interface. If it
receives a general query on any of its VLAN member, it checks the IP source address of the incoming frame.
If the IP SA in the incoming IGMP general query frame is lower than the IP address of the VLAN interface, the switch disables its
IGMP snooping Querier functionality.
If the IP SA of the incoming IGMP general query is higher than the VLAN IP address, the switch continues to work as an IGMP
snooping Querier.
ip igmp snooping enable
Enable IGMP snooping on all or a single VLAN. This command is the master on/o switch to enable IGMP snooping.
Syntax
ip igmp snooping enable
To disable IGMP snooping, use the no ip igmp snooping enable command.
Defaults Disabled.
Command Modes
• CONFIGURATION
• INTERFACE VLAN
Command History
This guide is platform-specic. For command information about other platforms, refer to the relevant Dell
Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version Description
9.7(0.0) Introduced on the S6000-ON.
9.5(0.0) Introduced on the Z9500.
9.2(0.0) Introduced on the M I/O Aggregator. This command is supported in Programmable-
Mux (PMUX) mode only.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
Internet Group Management Protocol (IGMP)
667