Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) - Manual (Page 511)

Brocade 6910 Ethernet Access Switch Configuration Guide 455
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IGMP Snooping
Command Mode
Global Configuration
Command Usage
• Multicast Router Discovery (MRD) uses multicast router advertisement, multicast router
solicitation, and multicast router termination messages to discover multicast routers. Devices
send solicitation messages in order to solicit advertisement messages from multicast routers.
These messages are used to discover multicast routers on a directly attached link. Solicitation
messages are also sent whenever a multicast forwarding interface is initialized or re-initialized.
Upon receiving a solicitation on an interface with IP multicast forwarding and MRD enabled, a
router will respond with an advertisement.
• Advertisements are sent by routers to advertise that IP multicast forwarding is enabled. These
messages are sent unsolicited periodically on all router interfaces on which multicast
forwarding is enabled. They are sent upon the expiration of a periodic timer, as a part of a
router's start up procedure, during the restart of a multicast forwarding interface, and on
receipt of a solicitation message. When the multicast services provided to a VLAN is relatively
stable, the use of solicitation messages is not required and may be disabled using the
no ip
igmp snooping vlan mrd command.
• This command may also be used to disable multicast router solicitation messages when the
upstream router does not support MRD, to reduce the loading on a busy upstream router, or
when IGMP snooping is disabled in a VLAN.
Example
This example disables sending of multicast router solicitation messages on VLAN 1.
Console(config)#no ip igmp snooping vlan 1 mrd
Console(config)#
ip igmp snooping vlan proxy-address
This command configures a static source address for locally generated query and report messages
used by IGMP proxy reporting. Use the no form to restore the default source address.
Syntax
[no] ip igmp snooping vlan vlan-id proxy-address source-address
vlan-id - VLAN ID (Range: 1-4093)
source-address - The source address used for proxied IGMP query and report, and leave
messages. (Any valid IP unicast address)
Default Setting
0.0.0.0
Command Mode
Global Configuration
Command Usage
IGMP Snooping uses a null IP address of 0.0.0.0 for the source of IGMP query messages which are
proxied to downstream hosts to indicate that it is not the elected querier, but is only proxying these
messages as defined in RFC 4541. The switch also uses a null address in IGMP reports sent to
upstream ports.