Cisco Systems N3KC3064TFAL3 manual Configuring IGMP Snooping, Information About IGMP Snooping

C H A P T E R 13

Configuring IGMP Snooping

This chapter contains the following sections:

•Information About IGMP Snooping, page 135

•Configuring IGMP Snooping Parameters, page 138

•Verifying IGMP Snooping Configuration, page 141

Information About IGMP Snooping

The IGMP snooping software examines IGMP protocol messages within a VLAN to discover which interfaces are connected to hosts or other devices interested in receiving this traffic. Using the interface information, IGMP snooping can reduce bandwidth consumption in a multi-access LAN environment to avoid flooding the entire VLAN. The IGMP snooping feature tracks which ports are attached to multicast-capable routers to help it manage the forwarding of IGMP membership reports. The IGMP snooping software responds to topology change notifications.

Note IGMP snooping is supported on all Ethernet interfaces. The term snooping is used because Layer 3 control plane packets are intercepted and influence Layer 2 forwarding decisions.

Cisco NX-OS supports IGMPv2 and IGMPv3. IGMPv2 supports IGMPv1, and IGMPv3 supports IGMPv2. Although not all features of an earlier version of IGMP are supported, the features related to membership query and membership report messages are supported for all IGMP versions.

Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)

OL-26590-01 135