Configuration Guide User guide

FastIron Configuration Guide 1491
53-1002494-02
Chapter
35
IP Multicast Traffic Reduction for
FastIron WS and Brocade FCX and ICX Switches
Table 252 lists the individual Brocade FastIron switches and the IP multicast traffic reduction
features they support. These features are supported in the Layer 2, base Layer 3, edge Layer 3,
and full Layer 3 software images, except where explicitly noted.
IGMP snooping overview
When a device processes a multicast packet, by default, the device 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 do snooping in the reserved range. Data packets destined to
addresses in 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. In
addition, a static group with the drop option can discard multicast data packets to a specified
group in hardware, including addresses in the reserved range.
TABLE 252 Supported IP multicast reduction features
Feature FESX
FSX 800
FSX 1600
FWS FCX ICX 6610 ICX 6430
ICX 6450
IGMP v1/v2 Snooping Global For details about IP
multicast traffic reduction
on FastIron X Series
switches, refer to “IGMP
snooping configuration” on
page 1467.
Yes Yes Yes Yes
IGMP v3 Snooping Global Yes
(S,G)
Yes
(S,G)
Yes
(S,G)
Yes
IGMP v1/v2/v3 Snooping per VLAN Yes Yes Yes Yes
IGMP v2/v3 Fast Leave
(membership tracking)
Yes Yes Yes Yes
PIM-SM V2 Snooping Yes Yes Yes Yes
Multicast static group traffic filtering
(for snooping scenarios)
Yes Yes Yes Yes