SMC Networks SMC6824M , S, 3-222

C ONFIGURING THE S WITCH
3-222
Static IGMP Host Interface – For multicast applications that you need to
control more carefully, you can manually assign a multicast service to
specific interfaces on the switch (page 3-228).
Configuring IGMP Snooping and Query Parameters
You can configure the switch to forward multicast traffic intelligently.
Based on the IGMP query and report messages, the switch forwards traffic
only to the ports that request multicast traffic. This prevents the switch
from broadcasting the traffic to all ports and possibly disrupting network
performance.
Command Usage
•IGMP Snooping – This switch can passively snoop on IGMP Query
and Report packets transferred between IP multicast routers/switches
and IP multicast host groups to identify the IP multicast group members.
It simply monitors the IGMP packets passing through it, picks out the
group registration information, and configures multicast filters
accordingly.
•IGMP Query – A router, or multicast-enabled switch, can periodically
ask their hosts if they want to receive multicast traffic. If there is more
than one router/switch on the LAN performing IP multicasting, one of
these devices is elected “querier” and assumes the role of querying the
LAN for group members. It then propagates the service requests on to
any adjacent multicast switch/router to ensure that it will continue to
receive the multicast service.
Note: Multicast routers use this information, along with a multicast
routing protocol such as DVMRP or PIM, to support IP
multicasting across the Internet.
Command Attributes
•IGMP Status — When enabled, the switch will monitor network traffic
to determine which hosts want to receive multicast traffic. This is also
referred to as IGMP Snooping. (Default: Enabled)
•Act as IGMP Querier — When enabled, the switch can serve as the
Querier, which is responsible for asking hosts if they want to receive
multicast traffic. (Default: Enabled)