ip multicast

Sets IGMP globally on a device, and sets the IGMP mode as active or passive.
Syntax
ip multicast active
ip multicast passive
no ip multicast active
no ip multicast passive
Command Default

IGMP mode is passive.

Parameters
active
Configures IGMP active mode so that the device actively sends out IGMP queries to identify multicast groups on the network, and makes entries in the IGMP table based on the group membership reports it receives.
passive
Configures IGMP passive mode so that the device does not send queries but forwards reports to the router ports that receive queries. When passive mode is configured on a VLAN, queries are forwarded to the entire VLAN.
Modes

Global configuration mode

VLAN configuration mode

Usage Guidelines

Routers in the network generally handle mode. Configure active IGMP mode only on a device is in a standalone Layer 2 Switched network with no external IP multicast router attachments. If you want to configure active IGMP mode on a device in such a network, you should do so on only one device and leave the others configured as passive.

The IGMP mode configured on a VLAN overrides the mode configured globally.

The no form of the command restores the default.

Examples

The following example enables IGMP mode globally for a device and configures IGMP mode as active. 

device# configure terminal
device(config)# ip multicast active

The following example enables IGMP mode for VLAN 20 and configures IGMP mode as passive. 

device# configure terminal
device(config)# config vlan 20
device(config-vlan-20)# ip multicast active
Parent topic: Commands I