You can configure the switch as a member of a multicast group and discover multicast reachability in a
network. If all the multicast-capable routers and multilayer switches that you administer are members of
a multicast group, pinging that group causes all these devices to respond. The devices respond to ICMP
echo-request packets addressed to a group of which they are members. Another example is the multicast
trace-route tools provided in the software.

Caution

Performing this procedure might impact the CPU performance because the CPU will receive all data
traffic for the group address.

Beginning in privileged EXEC mode, follow these steps to configure the switch to be a member of a
group. This procedure is optional.

Table 44-3

Default IGMP Configuration

Feature

Default Setting

Multilayer switch as a member of a multicast group

No group memberships are defined.

Access to multicast groups

All groups are allowed on an interface.

IGMP version

Version 2 on all interfaces.

IGMP host-query message interval

60 seconds on all interfaces.

IGMP query timeout

60 seconds on all interfaces.

IGMP maximum query response time

10 seconds on all interfaces.

Multilayer switch as a statically connected member

Disabled.

Command

Purpose

Step 1

configure terminal

Enter global configuration mode.

Step 2

interface interface-id

Specify the interface to be configured, and enter interface configuration
mode.

Step 3

ip igmp join-group group-address

Configure the switch to join a multicast group.

By default, no group memberships are defined.

For group-address, specify the multicast IP address in dotted decimal
notation.