Supermicro SSE-G2252, User Manual

Page: 515 / 1401

Chapter 15: Multicast Filtering
Layer 2 IGMP (Snooping and Query for IPv4)
– 522 –
The only deviation from TR-101 is that the marking of IGMP traffic initiated
by the switch with priority bits as defined in R-250 is not supported.
C
ONFIGURING
IGMP
S
NOOPING AND
Q
UERY
P
ARAMETERS
Use the Multicast > IGMP Snooping > General page to configure the switch
to forward multicast traffic intelligently. Based on the IGMP query and
report messages, the switch forwards multicast traffic only to the ports
that request it. This prevents the switch from broadcasting the traffic to all
ports and possibly disrupting network performance.
CLI R
EFERENCES
•
“IGMP Snooping” on page 1151
C
OMMAND
U
SAGE
• 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 the multicast filters
accordingly.
N
OTE
:
If unknown multicast traffic enters a VLAN which has been
configured with a router port, the traffic is forwarded to that port. However,
if no router port exists on the VLAN, the traffic is dropped if unregistered
data flooding is disabled (default behavior), or flooded throughout the
VLAN if unregistered data flooding is enabled (see “Unregistered Data
Flooding” in the Command Attributes section).
•
IGMP Querier – 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 upstream multicast switch/router to ensure that it will continue to
receive the multicast service.
N
OTE
:
Multicast routers use this information from IGMP snooping and query
reports, along with a multicast routing protocol such as DVMRP or PIM, to
support IP multicasting across the Internet.
P
ARAMETERS
These parameters are displayed:
•
IGMP Snooping Status – When enabled, the switch will monitor
network traffic to determine which hosts want to receive multicast
traffic. This is referred to as IGMP Snooping. (Default: Enabled)
When IGMP snooping is enabled globally, the per VLAN interface
settings for IGMP snooping take precedence (see “Setting IGMP
Snooping Status per Interface” on page 530 ).