Layer 2 IGMP (Snooping and Query)
15-5
15
Enabling IGMP Immediate Leave
The switch can be configured to immediately delete a member port of a multicast
service if a leave packet is received at that port and the immediate-leave function is
enabled for the parent VLAN. This allows the switch to remove a port from the
multicast forwarding table without first having to send an IGMP group-specific query
to that interface.
Command Usage
• If immediate leave is
not
used, a multicast router (or querier) will send a
group-specific query message when an IGMPv2/v3 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 timeout period. Note that the timeout period
is determined by the IGMP Query Report Delay (see “Configuring IGMP Snooping
and Query Parameters” on page 15-3).
• 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.
• Immediate leave is only effective if IGMP snooping is enabled, and IGMPv2 or
IGMPv3 snooping is used.
• Immediate leave does not apply to a port if the switch has learned that a multicast
router is attached to it.
• Immediate leave can improve bandwidth usage for a network which frequently
experiences many IGMP host add and leave requests.
Command Attributes
•
VLAN
ID
– VLAN Identifier. (Range: 1-4093).
•
Immediate Leave
– Sets the status for immediate leave on the specified VLAN.
(Default: Disabled)
Web
– Click IGMP Snooping, IGMP Immediate Leave. Select the VLAN interface to
configure, set the status for immediate leave, and click Apply.
Figure 15-1 IGMP Immediate Leave
Summary of Contents for 8926EM
Page 6: ...ii ...
Page 34: ...Getting Started ...
Page 44: ...Introduction 1 10 1 ...
Page 62: ...Initial Configuration 2 18 2 ...
Page 64: ...Switch Management ...
Page 76: ...Configuring the Switch 3 12 3 ...
Page 118: ...Basic Management Tasks 4 42 4 ...
Page 164: ...User Authentication 6 28 6 ...
Page 176: ...Access Control Lists 7 12 7 ...
Page 284: ...Quality of Service 14 8 14 ...
Page 294: ...Multicast Filtering 15 10 15 ...
Page 300: ...Domain Name Service 16 6 16 ...
Page 310: ...Dynamic Host Configuration Protocol 17 10 17 ...
Page 320: ...Configuring Router Redundancy 18 10 18 ...
Page 344: ...IP Routing 19 24 19 ...
Page 356: ...Unicast Routing 20 12 20 Web Click Routing Protocol RIP Statistics Figure 20 5 RIP Statistics ...
Page 386: ...Unicast Routing 20 42 20 ...
Page 388: ...Command Line Interface ...
Page 400: ...Overview of the Command Line Interface 21 12 21 ...
Page 466: ...SNMP Commands 24 16 24 ...
Page 520: ...Access Control List Commands 26 18 26 ...
Page 546: ...Rate Limit Commands 30 2 30 ...
Page 612: ...VLAN Commands 34 24 34 ...
Page 626: ...Class of Service Commands 35 14 35 ...
Page 670: ...DHCP Commands 39 16 39 ...
Page 716: ...IP Interface Commands 41 36 41 ...
Page 768: ...IP Routing Commands 42 52 42 ...
Page 770: ...Appendices ...
Page 791: ......