9-94
Configuring Advanced Features
Multimedia Traffic Control with IP Multicast (IGMP)
Co
nf
ig
u
ri
ng Adva
nce
d
Feat
u
res
on IGMP without IP addressing is that the switch cannot become Querier on
any VLANs for which it has no IP address—so the network administrator must
ensure that another IGMP device will act as Querier and that an additional
IGMP device is available as a backup Querier.
Table 9-11.IGMP Operation With or Without IP Addressing
Fast-Leave IGMP
IGMP Operation Presents a “Delayed Leave” Problem.
Where multi-
ple IGMP clients are connected to the same port on an IGMP device (switch
or router), if only one IGMP client joins a given multicast group, then later
sends a Leave Group message and ceases to belong to that group, the IGMP
device retains that IGMP client in its IGMP table and continues forwarding
IGMP traffic to the IGMP client until the Querier triggers confirmation that no
other group members exist on the same port. This means that the switch
continues to transmit unnecessary multicast traffic through the port until the
Querier renews multicast group status.
IGMP Function Available With IP Addressing
Configured on the VLAN
Available
Without
IP
Addressing?
Operating Differences Without an IP Address
Drop multicast group traffic for which there
have been no join requests from IGMP clients
connected to ports on the VLAN.
Yes
None
Forward multicast group traffic to any port on
the VLAN that has received a join request for
that multicast group.
Yes
None
Forward join requests (reports) to the Querier.
Yes
None
Configure individual ports in the VLAN to
Auto
(the default)/
Blocked
, or
Forward
.
Yes
None
Configure IGMP traffic forwarding to normal or
high-priority forwarding.
Yes
None
Age-Out IGMP group addresses when the last
IGMP client on a port in the VLAN leaves the
group.
Yes
Requires that another IGMP device in the VLAN has an IP
address and can operate as Querier. This can be a multi-
cast router or another switch configured for IGMP oper-
ation. SMC recommends that the VLAN also include a
device operating as a backup Querier in case the device
operating as the primary Querier fails for any reason.
Support Fast-Leave IGMP (below) and Forced
Fast-Leave IGMP (page 9-100).
Yes
Support automatic Querier election.
No
Querier operation not available.
Operate as the Querier.
No
Querier operation not available.
Provide a backup Querier.
No
Querier operation not available.
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Страница 50: ...3 16 Using the Command Line Interface CLI CLI Control and Editing Using the Command Line Interface CLI ...
Страница 302: ...9 112 Configuring Advanced Features Spanning Tree Protocol STP Configuring Advanced Features ...
Страница 328: ...10 26 Monitoring and Analyzing Switch Operation Port Monitoring Features Monitoring and Analyzing Switch Operation ...
Страница 364: ...B 4 MAC Address Management Determining MAC Addresses MAC Address Management ...
Страница 386: ...10 Index Index ...
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