Cisco Systems EA6500 Manual De Usuario

With Release 12.1(8a)E and later releases, IGMP snooping supports IGMP version 3. Because the Layer 
2 table is (MAC-group, VLAN) based, with IGMPv3 hosts it is preferable to have only a single multicast 
source per MAC-group. A single multicast source per group allows IGMPv3 hosts connected to specific 
ports to receive traffic from a specific (source, group).

 shows the default IGMP snooping configuration.

Follow these guidelines and restrictions when configuring IGMP snooping and IGMP snooping querier:

IGMP snooping supports private VLANs. Private VLANs do not impose any restrictions on IGMP 
snooping.

IGMP snooping constrains traffic in MAC multicast groups 0100.5e00.0001 to 0100.5eff.ffff. 

IGMP snooping does not constrain Layer 2 multicasts generated by routing protocols.

The IGMP snooping querier supports IGMP version 2.

When enabled, the IGMP snooping querier does not start if it detects IGMP traffic from a multicast 
router.

When enabled, the IGMP snooping querier starts after 60 seconds with no IGMP traffic detected 
from a multicast router.

When enabled, the IGMP snooping querier disables itself if it detects IGMP traffic from a multicast 
router.

You can enable the IGMP snooping querier on all the Catalyst 6500 series switches in the VLAN. 
On each VLAN that is connected to switches that use IGMP to report interest in IP multicast traffic, 
you must set one switch as the IGMP querier. 

IGMP snooping querier

1

1.

Supported in Release 12.1(8a)E and later releases.

Disabled

IGMP snooping

Enabled

Multicast routers

None configured

IGMP snooping learning method

PIM/DVMRP

2

 

2.

PIM/DVMRP = Protocol Independent Multicast/Distance Vector Multicast Routing Protocol