3com 5500-SI Manual Do Utilizador
320
C
HAPTER
18: M
ULTICAST
P
ROTOCOL
Configuring Multicast
VLAN
In old multicast mode, when users in different VLANs order the same multicast group,
the multicast stream is copied to each of the VLANs. This mode wastes a lot of
bandwidth.
the multicast stream is copied to each of the VLANs. This mode wastes a lot of
bandwidth.
By configuring a multicast VLAN, adding switch ports to the multicast VLAN and
enabling IGMP Snooping, you can make users in different VLANs share the same
multicast VLAN. This saves bandwidth since multicast streams are transmitted only
within the multicast VLAN, and also guarantees security because the multicast VLAN
is isolated from user VLANs.
enabling IGMP Snooping, you can make users in different VLANs share the same
multicast VLAN. This saves bandwidth since multicast streams are transmitted only
within the multicast VLAN, and also guarantees security because the multicast VLAN
is isolated from user VLANs.
Multicast VLAN is mainly used in Layer 2 switching, but you must make corresponding
configuration on the Layer 3 switch.
configuration on the Layer 3 switch.
Table 317 describes the configuration tasks for multicast VLAN.
Configure the maximum
number of multicast groups
the port can join.
number of multicast groups
the port can join.
igmp-snooping group-limit [
vlan vlan-list |
overflow-replace ]
vlan vlan-list |
overflow-replace ]
Required
By default, there is no limit on
the number of the multicast
groups the port can join.
By default, there is no limit on
the number of the multicast
groups the port can join.
Table 316 Configure the maximum number of multicast groups on a port (continued)
Operation
Command
Description
Table 317 Configure multicast VLAN on Layer 3 switch
Operation
Command
Description
Enter system view
system-view
—
Create a VLAN and enter the
VLAN view
VLAN view
vlan vlan-id
vlan-id is a VLAN ID.
Exit the VLAN view
quit
—
Create a VLAN interface and
enter the VLAN interface view
enter the VLAN interface view
interface vlan-interface
vlan-id
vlan-id
—
Enable IGMP
igmp enable
Required
Exit the VLAN interface view
quit
—
Enter the view of the Ethernet
port connected to the Layer 2
switch
port connected to the Layer 2
switch
interface interface-type
interface-num
interface-num
—
Define the port as a trunk or
hybrid port
hybrid port
port link-type { trunk |
hybrid }
hybrid }
Required
Set the VLAN IDs allowed to
pass through the Ethernet
pass through the Ethernet
port hybrid vlan vlan-id-list {
tagged | untagged }
tagged | untagged }
Required
The multicast VLAN defined on
the Layer 2 switch must be
included and set as tagged.
The multicast VLAN defined on
the Layer 2 switch must be
included and set as tagged.
port trunk pvid vlan vlan-id
Table 318 Configure multicast VLAN on Layer 2 switch
Operation
Command
Description
Enter system view
system-view
—
Enable IGMP Snooping globally igmp-snooping enable
Required
Enter VLAN view
vlan vlan-id
vlan-id is a VLAN ID.
Enable IGMP Snooping on the
VLAN
VLAN
igmp-snooping enable
Required