Configuration Guide User guide

FastIron Configuration Guide 1461
53-1002494-02
Chapter
34
IP Multicast Traffic Reduction on Brocade
FastIron X Series switches
Table 251 lists the individual Brocade FastIron X Series switches and the IP multicast traffic
reduction features they support. These features are supported in the Layer 2, base Layer 3, and full
Layer 3 software images, except where explicitly noted.
IGMP snooping overview
When a device processes a multicast packet, by default, it broadcasts the packets to all ports
except the incoming port of a VLAN. Packets are flooded by hardware without going to the CPU. This
behavior causes some clients to receive unwanted traffic.
IGMP snooping provides multicast containment by forwarding traffic to only the ports that have
IGMP receivers for a specific multicast group (destination address). A device maintains the IGMP
group membership information by processing the IGMP reports and leave messages, so traffic can
be forwarded to ports receiving IGMP reports.
An IPv4 multicast address is a destination address in the range of 224.0.0.0 to 239.255.255.255.
Addresses of 224.0.0.X are reserved. Because packets destined for these addresses may require
VLAN flooding, devices do not snoop in the reserved range. Data packets destined to addresses in
the reserved range are flooded to the entire VLAN by hardware, and mirrored to the CPU. Multicast
data packets destined for the non-reserved range of addresses are snooped. A client must send
IGMP reports in order to receive traffic. If an application outside the reserved range requires VLAN
flooding, the user must configure a static group that applies to the entire VLAN.
TABLE 251 Supported IP multicast reduction features
Feature FESX
FSX 800
FSX 1600
FWS FCX ICX 6610 ICX 6430
ICX 6450
IGMP v1/v2 Snooping Global Yes For details about IP multicast traffic
reduction on FastIron WS and Brocade
FCX Series and Brocade ICX 6610
Series switches, refer to “IGMP
snooping configuration” on
page 1497.
Yes
IGMP v3 Snooping Global Yes (*,G) Yes
IGMP v1/v2/v3 Snooping per VLAN Yes Yes
IGMP v2/v3 Fast Leave (membership
tracking)
Yes Yes
PIM-SM V2 Snooping Yes Yes