57
Table of Contents
Linksys
•
By IPv4 Group Address—Select to enable the IPv4 group address
method for forwarding Multicast packets
•
By Source Specific IPv4 Group Address—Select to enable the source-
specific IPv4 group address method for forwarding Multicast packets
•
IPv6 Multicast Forwarding—Select one of the following options:
•
By MAC Address—Select to enable the MAC address method for
forwarding Multicast packets
•
By IPv6 Group Address—Select to enable the IPv4 group address
method for forwarding Multicast packets
•
By Source Specific IPv6 Group Address—Select to enable the source
specific IPv6 group address method for forwarding Multicast packets
STEP 3 Click Apply The Running Configuration file is updated
IGMP/MLD Snooping
Multicast registration is the process of listening and responding to Multicast
registration protocols The available protocols are IGMP for IPv4 and MLD
for IPv6
When IGMP/MLD snooping is enabled in a device on a VLAN, it analyzes the
IGMP/MLD packets it receives from the VLAN connected to the device and
Multicast routers in the network
When a device learns that a host is using IGMP/MLD messages to register to
receive a Multicast stream, optionally from a specific source, the device adds
the registration to the MFDB
The following versions are supported:
•
IGMP v1/v2/ v3
•
MLD v1/v2
NOTE:
The device supports IGMP/MLD Snooping only on static VLANs It does not
support IGMP/MLD Snooping on dynamic VLANs
When IGMP/MLD Snooping is enabled globally or on a VLAN, all IGMP/MLD
packets are forwarded to the CPU The CPU analyzes the incoming packets,
and determines the following:
•
Which ports are asking to join which Multicast groups on what VLAN
•
Which ports are connected to Multicast routers (Mrouters) that are
generating IGMP/MLD queries
•
Which ports are receiving PIM, DVMRP, or IGMP/MLD query protocols
These VLANs are displayed on the IGMP/MLD Snooping page
Ports, asking to join a specific Multicast group, issue an IGMP report that
specifies which group(s) the host wants to join This results in the creation of a
forwarding entry in the Multicast Forwarding Data Base
To support selective IPv6 Multicast forwarding, bridge Multicast filtering must be
enabled (in the Multicast > Feature Configuration page), and MLD Snooping must
be enabled globally and for each relevant VLAN in the MLD Snooping pages
IGMP Snooping
To enable IGMP Snooping and identify the device as an IGMP Snooping
Querier on a VLAN, do the following:
STEP 1 Click Configuration > Multicast > IGMP Snooping
STEP 2 Enable or disable IGMP Snooping
When IGMP Snooping is enabled globally, the device monitoring network
traffic can determine which hosts have requested to receive Multicast traffic
The device only performs IGMP Snooping if both IGMP snooping and Bridge
Multicast filtering are enabled
STEP 3 Select a VLAN, and click Edit Enter the parameters:
•
VLAN ID—Select the VLAN ID on which MLD snooping is defined
•
VLAN Settings
•
IGMP Snooping Status—Enable or disable the monitoring of network
traffic for the selected VLAN
•
Auto Learn MRouter Ports —Select to enable auto learning of the ports
to which the Mrouter is connected
•
Immediate Leave—Select to enable Immediate Leave to decrease the
time it takes to block a Multicast stream sent to a member port when
an MLD Group Leave message is received on that port
•
IGMP Querier—Select to enable the IGMP Querier
