IGMP Overview
Summit 200 Series Switch Installation and User Guide 233
IGMP Overview
To constrain the flooding of multicast traffic, configure Summit 200 series switch interfaces to use
Internet Group Management Protocol (IGMP) snooping so that multicast traffic is forwarded only to
interfaces associated with IP multicast entities. IGMP is a protocol used by an IP host to register its IP
multicast group membership with a router. Periodically, the router queries the multicast group to see if
the group is still in use. If the group is still active, a single IP host responds to the query, and group
registration is maintained. When configured to use IGMP snooping, a Summit 200 series switch
“snoops” on IGMP transmissions to keep track of multicast groups and member ports.
IGMP is enabled by default on the switch. However, the switch can be configured to disable the
generation of period IGMP query packets. IGMP query should be enabled when the switch is
configured to perform IP unicast routing.
IGMP snooping is a layer 2 function of the switch, and is enabled by default. It does not require
multicast routing to be enabled. It is also supported across all slot types on stacked configurations.
IGMP snooping optimizes the usage of network bandwidth and prevents multicast traffic from being
configure pim timer <hello interval> <join
prune interval> vlan [<vlan name>] Configures the global PIM-SM timers. Speci fy the
following:
•hello interval—The amount of time
before a hello message is sent out by the PIM
router. The valid range is from 1 to 65,519
seconds. The default is 30 seconds.
•join prune interval—The amount of
time before a join or a prune command is
executed. The valid range is from 1 to 65,519
seconds. The default is 60 seconds.
•vlan—Configures timers on all VLANs.
•vlan name—Configures timers on a specific
VLAN.
configure pim vlan [<vlan name> | all]
trusted-gateway [<access profile> | none] Configures a trusted neighbor policy. Specify the
following:
•vlan name—A specific VLAN by name.
•all—All VLANs.
•access profile—An access profile
•none—No access profile; all gateways are
trusted.
[enable | disable] ipmcforwarding {<vlan>
<vlan name>} Enables or disables IP multicast routing on an
interface.You may also optionally specify:
•vlan—Enables or disables PIM-SM on all
VLANs.
•vlan name—Enables or disables PIM-SM on
a specific VLAN.
[enable | disable] pim Enable or disable PIM-SM on the system.
show pim {detail | rp-set | {vlan} <vlan
name>} Displays the PIM configuration and statistics.
Table 69: PIM-SM Commands (continued)
Command Description