Chapter 14
| Multicast Filtering
Layer 2 IGMP (Snooping and Query for IPv4)
– 539 –
If immediate leave is not used, a multicast router (or querier) will send a group-
specific query message when an IGMPv2 group leave message is received. The
router/querier stops forwarding traffic for that group only if no host replies to
the query within the specified time out period. Note that this time out is set to
Last Member Query Interval * Robustness Variable (fixed at 2) as defined in RFC
2236.
If immediate leave is enabled, the switch assumes that only one host is
connected to the interface. Therefore, immediate leave should only be enabled
on an interface if it is connected to only one IGMP-enabled device, either a
service host or a neighbor running IGMP snooping.
This attribute is only effective if IGMP snooping is enabled, and IGMPv2 or
IGMPv3 snooping is used.
If immediate leave is enabled, the following options are provided:
■
By Group
– The switch assumes that only one host is connected to the
interface. Therefore, immediate leave should only be enabled on an
interface if it is connected to only one IGMP-enabled device, either a
service host or a neighbor running IGMP snooping.
■
By Host IP
– The switch will not send out a group-specific query when an
IGMPv2/v3 leave message is received. But will check if there are other hosts
joining the multicast group. Only when all hosts on that port leave the
group will the member port be deleted.
◆
Multicast Router Discovery
– MRD is used to discover which interfaces are
attached to multicast routers. (Default: Disabled)
◆
General Query Suppression
– Suppresses general queries except for ports
attached to downstream multicast hosts. (Default: Disabled)
By default, general query messages are flooded to all ports, except for the
multicast router through which they are received.
If general query suppression is enabled, then these messages are forwarded
only to downstream ports which have joined a multicast service.
◆
Proxy Reporting
– Enables IGMP Snooping with Proxy Reporting.
(Options: Enabled, Disabled, Using Global Status; Default: Using Global Status)
When proxy reporting is enabled with this command, the switch performs
“IGMP Snooping with Proxy Reporting” (as defined in DSL Forum TR-101, April
2006), including last leave, and query suppression.
Last leave sends out a proxy query when the last member leaves a multicast
group, and query suppression means that specific queries are not forwarded
from an upstream multicast router to hosts downstream from this device.
Rules Used for Proxy Reporting
When IGMP Proxy Reporting is disabled, the switch will use a null IP address for
the source of IGMP query and report messages unless a proxy query address
has been set.
Summary of Contents for GTL-2881
Page 34: ...Section I Getting Started 34 ...
Page 48: ...Section II Web Configuration 48 Unicast Routing on page 651 ...
Page 151: ...Chapter 4 Interface Configuration VLAN Trunking 151 Figure 69 Configuring VLAN Trunking ...
Page 152: ...Chapter 4 Interface Configuration VLAN Trunking 152 ...
Page 230: ...Chapter 8 Congestion Control Automatic Traffic Control 230 ...
Page 596: ...Chapter 14 Multicast Filtering Multicast VLAN Registration for IPv6 596 ...
Page 620: ...Chapter 15 IP Configuration Setting the Switch s IP Address IP Version 6 620 ...
Page 672: ...Section III Appendices 672 ...
Page 678: ...Appendix A Software Specifications Management Information Bases 678 ...
Page 688: ...Appendix C License Statement GPL Code Statement Notification of Compliance 688 ...
Page 696: ...Glossary 696 ...
Page 706: ...GTL 2881 GTL 2882 E112016 ST R01 ...